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smartctl - Unix, Linux Command

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NAME

smartctl - Control and Monitor Utility for SMART Disks

SYNOPSIS

smartctl [options] device

FULL PATH

/usr/sbin/smartctl

PACKAGE VERSION

smartmontools-5.38 released 2008/03/10 at 10:44:07 GMT

DESCRIPTION

smartctl controls the Self-Monitoring, Analysis and Reporting Technology (SMART) system built into many ATA-3 and later ATA, IDE and SCSI-3 hard drives. The purpose of SMART is to monitor the reliability of the hard drive and predict drive failures, and to carry out different types of drive self-tests. This version of smartctl is compatible with ATA/ATAPI-7 and earlier standards (see REFERENCES below)

smartctl is a command line utility designed to perform SMART tasks such as printing the SMART self-test and error logs, enabling and disabling SMART automatic testing, and initiating device self-tests. Note: if the user issues a SMART command that is (apparently) not implemented by the device, smartctl will print a warning message but issue the command anyway (see the -T, --tolerance option below). This should not cause problems: on most devices, unimplemented SMART commands issued to a drive are ignored and/or return an error.

smartctl also provides support for polling TapeAlert messages from SCSI tape drives and changers.

The user must specify the device to be controlled or interrogated as the final argument to smartctl. Device paths are as follows:

TagDescription
LINUX: Use the forms "/dev/hd[a-t]" for IDE/ATA devices, and "/dev/sd[a-z]" for SCSI devices. For SCSI Tape Drives and Changers with TapeAlert support use the devices "/dev/nst*" and "/dev/sg*". For SATA disks accessed with libata, use "/dev/sd[a-z]" and append "-d ata". For disks behind 3ware controllers you may need "/dev/sd[a-z]" or "/dev/twe[0-9]" or "/dev/twa[0-9]": see details below. For disks behind HighPoint RocketRAID controllers you may need "/dev/sd[a-z]". More general paths (such as devfs ones) may also be specified.
DARWIN: Use the forms /dev/disk[0-9] or equivalently disk[0-9] or equivalently /dev/rdisk[0-9]. Long forms are also available: please use '-h' to see some examples. Note that there is currently no Darwin SCSI support.
FREEBSD: Use the forms "/dev/ad[0-9]+" for IDE/ATA devices and "/dev/da[0-9]+" for SCSI devices.
NETBSD/OPENBSD: Use the form "/dev/wd[0-9]+c" for IDE/ATA devices. For SCSI disk and tape devices, use the device names "/dev/sd[0-9]+c" and "/dev/st[0-9]+c" respectively. Be sure to specify the correct "whole disk" partition letter for your architecture.
SOLARIS: Use the forms "/dev/rdsk/c?t?d?s?" for IDE/ATA and SCSI disk devices, and "/dev/rmt/*" for SCSI tape devices.
WINDOWS 9x/ME: Use the forms "/dev/hd[a-d]" for standard IDE/ATA devices accessed via SMARTVSD.VXD, and "/dev/hd[e-h]" for additional devices accessed via a patched SMARTVSE.VXD (see INSTALL file for details). Use the form "/dev/scsi[0-9][0-f]" for SCSI devices via an aspi dll on ASPI adapter 0-9, ID 0-15. The prefix "/dev/" is optional.
WINDOWS NT4/2000/XP/2003/Vista: Use the forms "/dev/sd[a-z]" for IDE/(S)ATA and SCSI disks "\\.\PhysicalDrive[0-25]" (where "a" maps to "0"). These disks can also be referred to as "/dev/pd[0-255]" for "\\.\PhysicalDrive[0-255]". ATA disks can also be referred to as "/dev/hd[a-z]" for "\\.\PhysicalDrive[0-25]". Use one the forms "/dev/tape[0-255]", "/dev/st[0-255]", or "/dev/nst[0-255]" for SCSI tape drives "\\.\Tape[0-255]".

Alternatively, drive letters "X:" or "X:\" may be used to specify the physical drive behind a mounted partition.

For disks behind 3ware 9000 controllers use "/dev/sd[a-z],N" where N specifies the disk number (3ware 'port') behind the controller providing the logical drive ('unit') specified by "/dev/sd[a-z]". Alternatively, use "/dev/tw_cli/cx/py" for controller x, port y to run the 'tw_cli' tool and parse the output. This provides limited monitoring ('-i', '-c', '-A' below) if SMART support is missing in the driver. Use "/dev/tw_cli/stdin" or "/dev/tw_cli/clip" to parse CLI or 3DM output from standard input or clipboard. The option '-d 3ware,N' is not necessary on Windows. The prefix "/dev/" is optional.

CYGWIN: See "WINDOWS NT4/2000/XP/2003/Vista" above.
OS/2,eComStation: Use the form "/dev/hd[a-z]" for IDE/ATA devices.
if '-' is specified as the device path, smartctl reads and interprets it’s own debug output from standard input. See '-r ataioctl' below for details.

Based on the device path, smartctl will guess the device type (ATA or SCSI). If necessary, the '-d' option can be used to over-ride this guess

Note that the printed output of smartctl displays most numerical values in base 10 (decimal), but some values are displayed in base 16 (hexadecimal). To distinguish them, the base 16 values are always displayed with a leading "0x", for example: "0xff". This man page follows the same convention.

OPTIONS

The options are grouped below into several categories. smartctl will execute the corresponding commands in the order: INFORMATION, ENABLE/DISABLE, DISPLAY DATA, RUN/ABORT TESTS.

SCSI devices only accept the options -h, -V, -i, -a, -A, -d, -s, -S,-H, -t, -C, -l background, -l error, -l selftest, -r, and -X. TapeAlert devices only accept the options -h, -V, -i, -a, -A, -d, -s, -S, -t, -l error, -l selftest, -r, and -H.

Long options are not supported on all systems. Use 'smartctl -h' to see the available options.

TagDescription
SHOW INFORMATION OPTIONS:
-h, --help, --usage
  Prints a usage message to STDOUT and exits.
-V, --version, --copyright, --license
  Prints version, copyright, license, home page and CVS-id information for your copy of smartctl to STDOUT and then exits. Please include this information if you are reporting bugs or problems.
-i, --info Prints the device model number, serial number, firmware version, and ATA Standard version/revision information. Says if the device supports SMART, and if so, whether SMART support is currently enabled or disabled. If the device supports Logical Block Address mode (LBA mode) print current user drive capacity in bytes. (If drive is has a user protected area reserved, or is "clipped", this may be smaller than the potential maximum drive capacity.) Indicates if the drive is in the smartmontools database (see '-v' options below). If so, the drive model family may also be printed. If '-n' (see below) is specified, the power mode of the drive is printed.
-a, --all Prints all SMART information about the disk, or TapeAlert information about the tape drive or changer. For ATA devices this is equivalent to
'-H -i -c -A -l error -l selftest -l selective'
and for SCSI, this is equivalent to
'-H -i -A -l error -l selftest'.
Note that for ATA disks this does not enable the '-l directory' option.

RUN-TIME BEHAVIOR OPTIONS:
-q TYPE, --quietmode=TYPE
  Specifies that smartctl should run in one of the two quiet modes described here. The valid arguments to this option are:

errorsonly - only print: For the '-l error' option, if nonzero, the number of errors recorded in the SMART error log and the power-on time when they occurred; For the '-l selftest' option, errors recorded in the device self-test log; For the '-H' option, SMART "disk failing" status or device Attributes (pre-failure or usage) which failed either now or in the past; For the '-A' option, device Attributes (pre-failure or usage) which failed either now or in the past.

silent - print no output. The only way to learn about what was found is to use the exit status of smartctl (see RETURN VALUES below).

noserial - Do not print the serial number of the device.

-d TYPE, --device=TYPE
  Specifies the type of the device. The valid arguments to this option are ata, scsi, sat, marvell, 3ware,N, and hpt,L/M, cciss,N or hpt,L/M/N. If this option is not used then smartctl will attempt to guess the device type from the device name.

The 'sat' device type is for ATA disks that have a SCSI to ATA Translation (SAT) Layer (SATL) between the disk and the operating system. SAT defines two ATA PASS THROUGH SCSI commands, one 12 bytes long and the other 16 bytes long that smartctl will utilize when this device type is selected. The default is the 16 byte variant which can be overridden with either '-d sat,12' or '-d sat,16'.

Under Linux, to look at SATA disks behind Marvell SATA controllers (using Marvell’s 'linuxIAL' driver rather than libata driver) use '-d marvell'. Such controllers show up as Marvell Technology Group Ltd. SATA I or II controllers using lspci, or using lspci -n show a vendor ID 0x11ab and a device ID of either 0x5040, 0x5041, 0x5080, 0x5081, 0x6041 or 0x6081. The 'linuxIAL' driver seems not (yet?) available in the Linux kernel source tree, but should be available from system vendors (ftp://ftp.aslab.com/ is known to provide a patch with the driver).

Under Linux and FreeBSD, to look at ATA disks behind 3ware SCSI RAID controllers, use syntax such as:

smartctl -a -d 3ware,2 /dev/sda
smartctl -a -d 3ware,0 /dev/twe0
smartctl -a -d 3ware,1 /dev/twa0
where in the argument 3ware,N, the integer N is the disk number (3ware 'port') within the 3ware ATA RAID controller. The allowed values of N are from 0 to 31 inclusive. The first two forms, which refer to devices /dev/sda-z and /dev/twe0-15, may be used with 3ware series 6000, 7000, and 8000 series controllers that use the 3x-xxxx driver. Note that the /dev/sda-z form is deprecated starting with the Linux 2.6 kernel series and may not be supported by the Linux kernel in the near future. The final form, which refers to devices /dev/twa0-15, must be used with 3ware 9000 series controllers, which use the 3w-9xxx driver.

Note that if the special character device nodes /dev/twa? and /dev/twe? do not exist, or exist with the incorrect major or minor numbers, smartctl will recreate them on the fly. Typically /dev/twa0 refers to the first 9000-series controller, /dev/twa1 refers to the second 9000 series controller, and so on. Likewise /dev/twe0 refers to the first 6/7/8000-series controller, /dev/twa1 refers to the second 6/7/8000 series controller, and so on.

Note that for the 6/7/8000 controllers, any of the physical disks can be queried or examined using any of the 3ware’s SCSI logical device /dev/sd? entries. Thus, if logical device /dev/sda is made up of two physical disks (3ware ports zero and one) and logical device /dev/sdb is made up of two other physical disks (3ware ports two and three) then you can examine the SMART data on any of the four physical disks using either SCSI device /dev/sda or /dev/sdb. If you need to know which logical SCSI device a particular physical disk (3ware port) is associated with, use the dmesg or SYSLOG output to show which SCSI ID corresponds to a particular 3ware unit, and then use the 3ware CLI or 3dm tool to determine which ports (physical disks) correspond to particular 3ware units.

If the value of N corresponds to a port that does not exist on the 3ware controller, or to a port that does not physically have a disk attached to it, the behavior of smartctl depends upon the specific controller model, firmware, Linux kernel and platform. In some cases you will get a warning message that the device does not exist. In other cases you will be presented with 'void' data for a non-existent device.

Note that if the /dev/sd? addressing form is used, then older 3w-xxxx drivers do not pass the "Enable Autosave" ('-S on') and "Enable Automatic Offline" ('-o on') commands to the disk, and produce these types of harmless syslog error messages instead: "3w-xxxx: tw_ioctl(): Passthru size (123392) too big". This can be fixed by upgrading to version 1.02.00.037 or later of the 3w-xxxx driver, or by applying a patch to older versions. See http://smartmontools.sourceforge.net/ for instructions. Alternatively, use the character device /dev/twe0-15 interface.

The selective self-test functions ('-t select,A-B') are only supported using the character device interface /dev/twa0-15 and /dev/twe0-15. The necessary WRITE LOG commands can not be passed through the SCSI interface.

3ware controllers are supported under Linux, FreeBSD and Windows.

To look at (S)ATA disks behind HighPoint RocketRAID controllers, use syntax such as:

smartctl -a -d hpt,1/3 /dev/sda
or
smartctl -a -d hpt,1/2/3 /dev/sda
where in the argument hpt,L/M or hpt,L/M/N, the integer L is the controller id, the integer M is the channel number, and the integer N is the PMPort number if it is available. The allowed values of L are from 1 to 4 inclusive, M are from 1 to 8 inclusive and N from 1 to 4 if PMPort available. Note that the /dev/sda-z form should be the device node which stands for the disks derived from the HighPoint RocketRAID controllers. And also these values are limited by the model of the HighPoint RocketRAID controller.

HighPoint RocketRAID controllers are currently ONLY supported under Linux.

cciss controllers are currently ONLY supported under Linux.

-T TYPE, --tolerance=TYPE
  Specifies how tolerant smartctl should be of ATA and SMART command failures.

The behavior of smartctl depends upon whether the command is "optional" or "mandatory". Here "mandatory" means "required by the ATA/ATAPI-5 Specification if the device implements the SMART command set" and "optional" means "not required by the ATA/ATAPI-5 Specification even if the device implements the SMART command set." The "mandatory" ATA and SMART commands are: (1) ATA IDENTIFY DEVICE, (2) SMART ENABLE/DISABLE ATTRIBUTE AUTOSAVE, (3) SMART ENABLE/DISABLE, and (4) SMART RETURN STATUS.

The valid arguments to this option are:

normal - exit on failure of any mandatory SMART command, and ignore all failures of optional SMART commands. This is the default. Note that on some devices, issuing unimplemented optional SMART commands doesn't cause an error. This can result in misleading smartctl messages such as "Feature X not implemented", followed shortly by "Feature X: enabled". In most such cases, contrary to the final message, Feature X is not enabled.

conservative - exit on failure of any optional SMART command.

permissive - ignore failure(s) of mandatory SMART commands. This option may be given more than once. Each additional use of this option will cause one more additional failure to be ignored. Note that the use of this option can lead to messages like "Feature X not implemented", followed shortly by "Error: unable to enable Feature X". In a few such cases, contrary to the final message, Feature X is enabled.

verypermissive - equivalent to giving a large number of '-T permissive' options: ignore failures of any number of mandatory SMART commands. Please see the note above.

-b TYPE, --badsum=TYPE
  Specifies the action smartctl should take if a checksum error is detected in the: (1) Device Identity Structure, (2) SMART Self-Test Log Structure, (3) SMART Attribute Value Structure, (4) SMART Attribute Threshold Structure, or (5) ATA Error Log Structure.

The valid arguments to this option are:

warn - report the incorrect checksum but carry on in spite of it. This is the default.

exit - exit smartctl.

ignore - continue silently without issuing a warning.

-r TYPE, --report=TYPE
  Intended primarily to help smartmontools developers understand the behavior of smartmontools on non-conforming or poorly conforming hardware. This option reports details of smartctl transactions with the device. The option can be used multiple times. When used just once, it shows a record of the ioctl() transactions with the device. When used more than once, the detail of these ioctl() transactions are reported in greater detail. The valid arguments to this option are:

ioctl - report all ioctl() transactions.

ataioctl - report only ioctl() transactions with ATA devices.

scsiioctl - report only ioctl() transactions with SCSI devices. Invoking this once shows the SCSI commands in hex and the corresponding status. Invoking it a second time adds a hex listing of the first 64 bytes of data send to, or received from the device.

Any argument may include a positive integer to specify the level of detail that should be reported. The argument should be followed by a comma then the integer with no spaces. For example, ataioctl,2 The default level is 1, so '-r ataioctl,1' and '-r ataioctl' are equivalent.

For testing purposes, the output of '-r ataioctl,2' can later be parsed by smartctl itself if '-' is used as device path argument. The ATA command input parameters, sector data and return values are reconstructed from the debug report read from stdin. Then smartctl internally simulates an ATA device with the same behaviour. This is does not work for SCSI devices yet.

-n POWERMODE, --nocheck=POWERMODE
  Specifieds if smartctl should exit before performing any checks when the device is in a low-power mode. It may be used to prevent a disk from being spun-up by smartctl. The power mode is ignored by default. The allowed values of POWERMODE are:

never - check the device always, but print the power mode if '-i' is specified.

sleep - check the device unless it is in SLEEP mode.

standby - check the device unless it is in SLEEP or STANDBY mode. In these modes most disks are not spinning, so if you want to prevent a disk from spinning up, this is probably what you want.

idle - check the device unless it is in SLEEP, STANDBY or IDLE mode. In the IDLE state, most disks are still spinning, so this is probably not what you want.

SMART FEATURE ENABLE/DISABLE COMMANDS:
Note: if multiple options are used to both enable and disable a feature, then both the enable and disable commands will be issued. The enable command will always be issued before the corresponding disable command.
-s VALUE, --smart=VALUE
  Enables or disables SMART on device. The valid arguments to this option are on and off. Note that the command '-s on' (perhaps used with with the '-o on' and '-S on' options) should be placed in a start-up script for your machine, for example in rc.local or rc.sysinit. In principle the SMART feature settings are preserved over power-cycling, but it doesn't hurt to be sure. It is not necessary (or useful) to enable SMART to see the TapeAlert messages.
-o VALUE, --offlineauto=VALUE
  Enables or disables SMART automatic offline test, which scans the drive every four hours for disk defects. This command can be given during normal system operation. The valid arguments to this option are on and off.

Note that the SMART automatic offline test command is listed as "Obsolete" in every version of the ATA and ATA/ATAPI Specifications. It was originally part of the SFF-8035i Revision 2.0 specification, but was never part of any ATA specification. However it is implemented and used by many vendors. [Good documentation can be found in IBM's Official Published Disk Specifications. For example the IBM Travelstar 40GNX Hard Disk Drive Specifications (Revision 1.1, 22 April 2002, Publication # 1541, Document S07N-7715-02) page 164. You can also read the SFF-8035i Specification -- see REFERENCES below.] You can tell if automatic offline testing is supported by seeing if this command enables and disables it, as indicated by the 'Auto Offline Data Collection' part of the SMART capabilities report (displayed with '-c').

SMART provides three basic categories of testing. The first category, called "online" testing, has no effect on the performance of the device. It is turned on by the '-s on' option.

The second category of testing is called "offline" testing. This type of test can, in principle, degrade the device performance. The '-o on' option causes this offline testing to be carried out, automatically, on a regular scheduled basis. Normally, the disk will suspend offline testing while disk accesses are taking place, and then automatically resume it when the disk would otherwise be idle, so in practice it has little effect. Note that a one-time offline test can also be carried out immediately upon receipt of a user command. See the '-t offline' option below, which causes a one-time offline test to be carried out immediately.

The choice (made by the SFF-8035i and ATA specification authors) of the word testing for these first two categories is unfortunate, and often leads to confusion. In fact these first two categories of online and offline testing could have been more accurately described as online and offline data collection.

The results of this automatic or immediate offline testing (data collection) are reflected in the values of the SMART Attributes. Thus, if problems or errors are detected, the values of these Attributes will go below their failure thresholds; some types of errors may also appear in the SMART error log. These are visible with the '-A' and '-l error' options respectively.

Some SMART attribute values are updated only during off-line data collection activities; the rest are updated during normal operation of the device or during both normal operation and off-line testing. The Attribute value table produced by the '-A' option indicates this in the UPDATED column. Attributes of the first type are labeled "Offline" and Attributes of the second type are labeled "Always".

The third category of testing (and the only category for which the word 'testing' is really an appropriate choice) is "self" testing. This third type of test is only performed (immediately) when a command to run it is issued. The '-t' and '-X' options can be used to carry out and abort such self-tests; please see below for further details.

Any errors detected in the self testing will be shown in the SMART self-test log, which can be examined using the '-l selftest' option.

Note: in this manual page, the word "Test" is used in connection with the second category just described, e.g. for the "offline" testing. The words "Self-test" are used in connection with the third category.

-S VALUE, --saveauto=VALUE
  Enables or disables SMART autosave of device vendor-specific Attributes. The valid arguments to this option are on and off. Note that this feature is preserved across disk power cycles, so you should only need to issue it once.

For SCSI devices this toggles the value of the Global Logging Target Save Disabled (GLTSD) bit in the Control Mode Page. Some disk manufacturers set this bit by default. This prevents error counters, power-up hours and other useful data from being placed in non-volatile storage, so these values may be reset to zero the next time the device is power-cycled. If the GLTSD bit is set then 'smartctl -a' will issue a warning. Use on to clear the GLTSD bit and thus enable saving counters to non-volatile storage. For extreme streaming-video type applications you might consider using off to set the GLTSD bit.

SMART READ AND DISPLAY DATA OPTIONS:
-H, --health
  Check: Ask the device to report its SMART health status or pending TapeAlert messages. SMART status is based on information that it has gathered from online and offline tests, which were used to determine/update its SMART vendor-specific Attribute values. TapeAlert status is obtained by reading the TapeAlert log page.

If the device reports failing health status, this means either that the device has already failed, or that it is predicting its own failure within the next 24 hours. If this happens, use the '-a' option to get more information, and get your data off the disk and to someplace safe as soon as you can.

-c, --capabilities
  Prints only the generic SMART capabilities. These show what SMART features are implemented and how the device will respond to some of the different SMART commands. For example it shows if the device logs errors, if it supports offline surface scanning, and so on. If the device can carry out self-tests, this option also shows the estimated time required to run those tests.

Note that the time required to run the Self-tests (listed in minutes) are fixed. However the time required to run the Immediate Offline Test (listed in seconds) is variable. This means that if you issue a command to perform an Immediate Offline test with the '-t offline' option, then the time may jump to a larger value and then count down as the Immediate Offline Test is carried out. Please see REFERENCES below for further information about the the flags and capabilities described by this option.

-A, --attributes
  Prints only the vendor specific SMART Attributes. The Attributes are numbered from 1 to 253 and have specific names and ID numbers. For example Attribute 12 is "power cycle count": how many times has the disk been powered up.

Each Attribute has a "Raw" value, printed under the heading "RAW_VALUE", and a "Normalized" value printed under the heading "VALUE". [Note: smartctl prints these values in base-10.] In the example just given, the "Raw Value" for Attribute 12 would be the actual number of times that the disk has been power-cycled, for example 365 if the disk has been turned on once per day for exactly one year. Each vendor uses their own algorithm to convert this "Raw" value to a "Normalized" value in the range from 1 to 254. Please keep in mind that smartctl only reports the different Attribute types, values, and thresholds as read from the device. It does not carry out the conversion between "Raw" and "Normalized" values: this is done by the disk's firmware.

The conversion from Raw value to a quantity with physical units is not specified by the SMART standard. In most cases, the values printed by smartctl are sensible. For example the temperature Attribute generally has its raw value equal to the temperature in Celsius. However in some cases vendors use unusual conventions. For example the Hitachi disk on my laptop reports its power-on hours in minutes, not hours. Some IBM disks track three temperatures rather than one, in their raw values. And so on.

Each Attribute also has a Threshold value (whose range is 0 to 255) which is printed under the heading "THRESH". If the Normalized value is less than or equal to the Threshold value, then the Attribute is said to have failed. If the Attribute is a pre-failure Attribute, then disk failure is imminent.

Each Attribute also has a "Worst" value shown under the heading "WORST". This is the smallest (closest to failure) value that the disk has recorded at any time during its lifetime when SMART was enabled. [Note however that some vendors firmware may actually increase the "Worst" value for some "rate-type" Attributes.]

The Attribute table printed out by smartctl also shows the "TYPE" of the Attribute. Attributes are one of two possible types: Pre-failure or Old age. Pre-failure Attributes are ones which, if less than or equal to their threshold values, indicate pending disk failure. Old age, or usage Attributes, are ones which indicate end-of-product life from old-age or normal aging and wearout, if the Attribute value is less than or equal to the threshold. Please note: the fact that an Attribute is of type ’Pre-fail’ does not mean that your disk is about to fail! It only has this meaning if the Attribute's current Normalized value is less than or equal to the threshold value.

If the Attribute's current Normalized value is less than or equal to the threshold value, then the "WHEN_FAILED" column will display "FAILING_NOW". If not, but the worst recorded value is less than or equal to the threshold value, then this column will display "In_the_past". If the "WHEN_FAILED" column has no entry (indicated by a dash: '-') then this Attribute is OK now (not failing) and has also never failed in the past.

The table column labeled "UPDATED" shows if the SMART Attribute values are updated during both normal operation and off-line testing, or only during offline testing. The former are labeled "Always" and the latter are labeled "Offline".

So to summarize: the Raw Attribute values are the ones that might have a real physical interpretation, such as "Temperature Celsius", "Hours", or "Start-Stop Cycles". Each manufacturer converts these, using their detailed knowledge of the disk's operations and failure modes, to Normalized Attribute values in the range 1-254. The current and worst (lowest measured) of these Normalized Attribute values are stored on the disk, along with a Threshold value that the manufacturer has determined will indicate that the disk is going to fail, or that it has exceeded its design age or aging limit. smartctl does not calculate any of the Attribute values, thresholds, or types, it merely reports them from the SMART data on the device.

Note that starting with ATA/ATAPI-4, revision 4, the meaning of these Attribute fields has been made entirely vendor-specific. However most ATA/ATAPI-5 disks seem to respect their meaning, so we have retained the option of printing the Attribute values.

For SCSI devices the "attributes" are obtained from the temperature and start-stop cycle counter log pages. Certain vendor specific attributes are listed if recognised. The attributes are output in a relatively free format (compared with ATA disk attributes).

-l TYPE, --log=TYPE
  Prints either the SMART Error Log, the SMART Self-Test Log, the SMART Selective Self-Test Log [ATA only], the Log Directory [ATA only], or the Background Scan Results Log [SCSI only]. The valid arguments to this option are:

error - prints only the SMART error log. SMART disks maintain a log of the most recent five non-trivial errors. For each of these errors, the disk power-on lifetime at which the error occurred is recorded, as is the device status (idle, standby, etc) at the time of the error. For some common types of errors, the Error Register (ER) and Status Register (SR) values are decoded and printed as text. The meanings of these are:

   ABRT:  Command ABoRTed
   AMNF:  Address Mark Not Found
   CCTO:  Command Completion Timed Out
   EOM:   End Of Media
   ICRC:  Interface Cyclic Redundancy Code (CRC) error
   IDNF:  IDentity Not Found
   ILI:   (packet command-set specific)
   MC:    Media Changed
   MCR:   Media Change Request
   NM:    No Media
   obs:   obsolete
   TK0NF: TracK 0 Not Found
   UNC:   UNCorrectable Error in Data
   WP:    Media is Write Protected
In addition, up to the last five commands that preceded the error are listed, along with a timestamp measured from the start of the corresponding power cycle. This is displayed in the form Dd+HH:MM:SS.msec where D is the number of days, HH is hours, MM is minutes, SS is seconds and msec is milliseconds. [Note: this time stamp wraps after 2^32 milliseconds, or 49 days 17 hours 2 minutes and 47.296 seconds.] The key ATA disk registers are also recorded in the log. The final column of the error log is a text-string description of the ATA command defined by the Command Register (CR) and Feature Register (FR) values. Commands that are obsolete in the most current (ATA-7) spec are listed like this: READ LONG (w/ retry) [OBS-4], indicating that the command became obsolete with or in the ATA-4 specification. Similarly, the notation [RET-N] is used to indicate that a command was retired in the ATA-N specification. Some commands are not defined in any version of the ATA specification but are in common use nonetheless; these are marked [NS], meaning non-standard.

The ATA Specification (ATA-5 Revision 1c, Section 8.41.6.8.2) says: "Error log structures shall include UNC errors, IDNF errors for which the address requested was valid, servo errors, write fault errors, etc. Error log data structures shall not include errors attributed to the receipt of faulty commands such as command codes not implemented by the device or requests with invalid parameters or invalid addresses." The definitions of these terms are:
UNC (UNCorrectable): data is uncorrectable. This refers to data which has been read from the disk, but for which the Error Checking and Correction (ECC) codes are inconsistent. In effect, this means that the data can not be read.
IDNF (ID Not Found): user-accessible address could not be found. For READ LOG type commands, IDNF can also indicate that a device data log structure checksum was incorrect.

If the command that caused the error was a READ or WRITE command, then the Logical Block Address (LBA) at which the error occurred will be printed in base 10 and base 16. The LBA is a linear address, which counts 512-byte sectors on the disk, starting from zero. (Because of the limitations of the SMART error log, if the LBA is greater than 0xfffffff, then either no error log entry will be made, or the error log entry will have an incorrect LBA. This may happen for drives with a capacity greater than 128 GiB or 137 GB.) On Linux systems the smartmontools web page has instructions about how to convert the LBA address to the name of the disk file containing the erroneous disk sector.

Please note that some manufacturers ignore the ATA specifications, and make entries in the error log if the device receives a command which is not implemented or is not valid.

error [SCSI] - prints the error counter log pages for reads, write and verifies. The verify row is only output if it has an element other than zero.

selftest - prints the SMART self-test log. The disk maintains a self-test log showing the results of the self tests, which can be run using the '-t' option described below. For each of the most recent twenty-one self-tests, the log shows the type of test (short or extended, off-line or captive) and the final status of the test. If the test did not complete successfully, then the percentage of the test remaining is shown. The time at which the test took place, measured in hours of disk lifetime, is also printed. If any errors were detected, the Logical Block Address (LBA) of the first error is printed in decimal notation. On Linux systems the smartmontools web page has instructions about how to convert this LBA address to the name of the disk file containing the erroneous block.

selftest [SCSI] - the self-test log for a SCSI device has a slightly different format than for an ATA device. For each of the most recent twenty self-tests, it shows the type of test and the status (final or in progress) of the test. SCSI standards use the terms "foreground" and "background" (rather than ATA's corresponding "captive" and "off-line") and "short" and "long" (rather than ATA's corresponding "short" and "extended") to describe the type of the test. The printed segment number is only relevant when a test fails in the third or later test segment. It identifies the test that failed and consists of either the number of the segment that failed during the test, or the number of the test that failed and the number of the segment in which the test was run, using a vendor-specific method of putting both numbers into a single byte. The Logical Block Address (LBA) of the first error is printed in hexadecimal notation. On Linux systems the smartmontools web page has instructions about how to convert this LBA address to the name of the disk file containing the erroneous block. If provided, the SCSI Sense Key (SK), Additional Sense Code (ASC) and Additional Sense Code Qualifier (ASQ) are also printed. The self tests can be run using the '-t' option described below (using the ATA test terminology).

selective [ATA] - Some ATA-7 disks (example: Maxtor) also maintain a selective self-test log. Please see the '-t select' option below for a description of selective self-tests. The selective self-test log shows the start/end Logical Block Addresses (LBA) of each of the five test spans, and their current test status. If the span is being tested or the remainder of the disk is being read-scanned, the current 65536-sector block of LBAs being tested is also displayed. The selective self-test log also shows if a read-scan of the remainder of the disk will be carried out after the selective self-test has completed (see '-t afterselect' option) and the time delay before restarting this read-scan if it is interrupted (see '-t pending' option). This is a new smartmontools feature; please report unusual or incorrect behavior to the smartmontools-support mailing list.

directory - if the device supports the General Purpose Logging feature set (ATA-6 and ATA-7 only) then this prints the Log Directory (the log at address 0). The Log Directory shows what logs are available and their length in sectors (512 bytes). The contents of the logs at address 1 [Summary SMART error log] and at address 6 [SMART self-test log] may be printed using the previously-described error and selftest arguments to this option. [Please note: this is a new, experimental feature. We would like to add support for printing the contents of extended and comprehensive SMART self-test and error logs. If your disk supports these, and you would like to assist, please contact the smartmontools developers.]

background [SCSI] - the background scan results log outputs information derived from Background Media Scans (BMS) done after power up and/or periodocally (e.g. every 24 hours) on recent SCSI disks. If supported, the BMS status is output first, indicating whether a background scan is currently underway (and if so a progress percentage), the amount of time the disk has been powered up and the number of scans already completed. Then there is a header and a line for each background scan "event". These will typically be either recovered or unrecoverable errors. That latter group may need some attention. There is a description of the background scan mechansim in section 4.18 of SBC-3 revision 6 (see www.t10.org ).

scttemp, scttempsts, scttemphist [ATA] - [NEW EXPERIMENTAL SMARTCTL FEATURE] prints the disk temperature information provided by the SMART Command Transport (SCT) commands. The option 'scttempsts' prints current temperature and temperature ranges returned by the SCT Status command, 'scttemphist' prints temperature limits and the temperature history table returned by the SCT Data Table command, and 'scttemp' prints both. The temperature values are preserved across power cycles. The default temperature logging interval is 1 minute and can be configured with the '-t scttempint,N[,p]' option, see below. The SCT commands are specified in the proposed ATA-8 Command Set (ACS), and are already implemented in some recent ATA-7 disks.

-v N,OPTION, --vendorattribute=N,OPTION
  Sets a vendor-specific display OPTION for Attribute N. This option may be used multiple times. Valid arguments to this option are:

help - Prints (to STDOUT) a list of all valid arguments to this option, then exits.

9,minutes - Raw Attribute number 9 is power-on time in minutes. Its raw value will be displayed in the form "Xh+Ym". Here X is hours, and Y is minutes in the range 0-59 inclusive. Y is always printed with two digits, for example "06" or "31" or "00".

9,seconds - Raw Attribute number 9 is power-on time in seconds. Its raw value will be displayed in the form "Xh+Ym+Zs". Here X is hours, Y is minutes in the range 0-59 inclusive, and Z is seconds in the range 0-59 inclusive. Y and Z are always printed with two digits, for example "06" or "31" or "00".

9,halfminutes - Raw Attribute number 9 is power-on time, measured in units of 30 seconds. This format is used by some Samsung disks. Its raw value will be displayed in the form "Xh+Ym". Here X is hours, and Y is minutes in the range 0-59 inclusive. Y is always printed with two digits, for example "06" or "31" or "00".

9,temp - Raw Attribute number 9 is the disk temperature in Celsius.

192,emergencyretractcyclect - Raw Attribute number 192 is the Emergency Retract Cycle Count.

193,loadunload - Raw Attribute number 193 contains two values. The first is the number of load cycles. The second is the number of unload cycles. The difference between these two values is the number of times that the drive was unexpectedly powered off (also called an emergency unload). As a rule of thumb, the mechanical stress created by one emergency unload is equivalent to that created by one hundred normal unloads.

194,10xCelsius - Raw Attribute number 194 is ten times the disk temperature in Celsius. This is used by some Samsung disks (example: model SV1204H with RK100-13 firmware).

194,unknown - Raw Attribute number 194 is NOT the disk temperature, and its interpretation is unknown. This is primarily useful for the -P (presets) option.

198,offlinescanuncsectorct - Raw Attribute number 198 is the Offline Scan UNC Sector Count.

200,writeerrorcount - Raw Attribute number 200 is the Write Error Count.

201,detectedtacount - Raw Attribute number 201 is the Detected TA Count.

220,temp - Raw Attribute number 220 is the disk temperature in Celsius.

Note: a table of hard drive models, listing which Attribute corresponds to temperature, can be found at: http://www.guzu.net/linux/hddtemp.db

N,raw8 - Print the Raw value of Attribute N as six 8-bit unsigned base-10 integers. This may be useful for decoding the meaning of the Raw value. The form 'N,raw8' prints Raw values for ALL Attributes in this form. The form (for example) '123,raw8' only prints the Raw value for Attribute 123 in this form.

N,raw16 - Print the Raw value of Attribute N as three 16-bit unsigned base-10 integers. This may be useful for decoding the meaning of the Raw value. The form 'N,raw16' prints Raw values for ALL Attributes in this form. The form (for example) '123,raw16' only prints the Raw value for Attribute 123 in this form.

N,raw48 - Print the Raw value of Attribute N as a 48-bit unsigned base-10 integer. This may be useful for decoding the meaning of the Raw value. The form 'N,raw48' prints Raw values for ALL Attributes in this form. The form (for example) '123,raw48' only prints the Raw value for Attribute 123 in this form.

-F TYPE, --firmwarebug=TYPE
  Modifies the behavior of smartctl to compensate for some known and understood device firmware or driver bug. Except 'swapid', the arguments to this option are exclusive, so that only the final option given is used. The valid values are:

none - Assume that the device firmware obeys the ATA specifications. This is the default, unless the device has presets for '-F' in the device database (see note below).

samsung - In some Samsung disks (example: model SV4012H Firmware Version: RM100-08) some of the two- and four-byte quantities in the SMART data structures are byte-swapped (relative to the ATA specification). Enabling this option tells smartctl to evaluate these quantities in byte-reversed order. Some signs that your disk needs this option are (1) no self-test log printed, even though you have run self-tests; (2) very large numbers of ATA errors reported in the ATA error log; (3) strange and impossible values for the ATA error log timestamps.

samsung2 - In more recent Samsung disks (firmware revisions ending in "-23") the number of ATA errors reported is byte swapped. Enabling this option tells smartctl to evaluate this quantity in byte-reversed order. An indication that your Samsung disk needs this option is that the self-test log is printed correctly, but there are a very large number of errors in the SMART error log. This is because the error count is byte swapped. Thus a disk with five errors (0x0005) will appear to have 20480 errors (0x5000).

samsung3 - Some Samsung disks (at least SP2514N with Firmware VF100-37) report a self-test still in progress with 0% remaining when the test was already completed. Enabling this option modifies the output of the self-test execution status (see options '-c' or '-a' above) accordingly.

Note that an explicit '-F' option on the command line will over-ride any preset values for '-F' (see the '-P' option below).

swapid - Fixes byte swapped ATA identify strings (device name, serial number, firmware version) returned by some buggy device drivers.

-P TYPE, --presets=TYPE
  Specifies whether smartctl should use any preset options that are available for this drive. By default, if the drive is recognized in the smartmontools database, then the presets are used.

smartctl can automatically set appropriate options for known drives. For example, the Maxtor 4D080H4 uses Attribute 9 to stores power-on time in minutes whereas most drives use that Attribute to store the power-on time in hours. The command-line option '-v 9,minutes' ensures that smartctl correctly interprets Attribute 9 in this case, but that option is preset for the Maxtor 4D080H4 and so need not be specified by the user on the smartctl command line.

The argument show will show any preset options for your drive and the argument showall will show all known drives in the smartmontools database, along with their preset options. If there are no presets for your drive and you think there should be (for example, a -v or -F option is needed to get smartctl to display correct values) then please contact the smartmontools developers so that this information can be added to the smartmontools database. Contact information is at the end of this man page.

The valid arguments to this option are:

use - if a drive is recognized, then use the stored presets for it. This is the default. Note that presets will NOT over-ride additional Attribute interpretation ('-v N,something') command-line options or explicit '-F' command-line options..

ignore - do not use presets.

show - show if the drive is recognized in the database, and if so, its presets, then exit.

showall - list all recognized drives, and the presets that are set for them, then exit.

The '-P showall' option takes up to two optional arguments to match a specific drive type and firmware version. The command:

  smartctl -P showall
lists all entries, the command:
  smartctl -P showall 'MODEL'
lists all entries matching MODEL, and the command:
  smartctl -P showall 'MODEL' 'FIRMWARE'
lists all entries for this MODEL and a specific FIRMWARE version.

SMART RUN/ABORT OFFLINE TEST AND SELF-TEST OPTIONS:
-t TEST, --test=TEST
  Executes TEST immediately. The '-C' option can be used in conjunction with this option to run the short or long (and also for ATA devices, selective or conveyance) self-tests in captive mode (known as "foreground mode" for SCSI devices). Note that only one test type can be run at a time, so only one test type should be specified per command line. Note also that if a computer is shutdown or power cycled during a self-test, no harm should result. The self-test will either be aborted or will resume automatically.

The valid arguments to this option are:

offline - runs SMART Immediate Offline Test. This immediately starts the test described above. This command can be given during normal system operation. The effects of this test are visible only in that it updates the SMART Attribute values, and if errors are found they will appear in the SMART error log, visible with the '-l error' option. [In the case of SCSI devices runs the default self test in foreground. No entry is placed in the self test log.]

If the '-c' option to smartctl shows that the device has the "Suspend Offline collection upon new command" capability then you can track the progress of the Immediate Offline test using the '-c' option to smartctl. If the '-c' option show that the device has the "Abort Offline collection upon new command" capability then most commands will abort the Immediate Offline Test, so you should not try to track the progress of the test with '-c', as it will abort the test.

short - runs SMART Short Self Test (usually under ten minutes). [Note: in the case of SCSI devices, this command option runs the "Background short" self-test.] This command can be given during normal system operation (unless run in captive mode - see the '-C' option below). This is a test in a different category than the immediate or automatic offline tests. The "Self" tests check the electrical and mechanical performance as well as the read performance of the disk. Their results are reported in the Self Test Error Log, readable with the '-l selftest' option. Note that on some disks the progress of the self-test can be monitored by watching this log during the self-test; with other disks use the '-c' option to monitor progress.

long - runs SMART Extended Self Test (tens of minutes). [Note: in the case of SCSI devices, this command option runs the "Background long" self-test.] This is a longer and more thorough version of the Short Self Test described above. Note that this command can be given during normal system operation (unless run in captive mode - see the '-C' option below).

conveyance - [ATA ONLY] runs a SMART Conveyance Self Test (minutes). This self-test routine is intended to identify damage incurred during transporting of the device. This self-test routine should take on the order of minutes to complete. Note that this command can be given during normal system operation (unless run in captive mode - see the '-C' option below).

select,N-M, select,N+SIZE - [ATA ONLY] [EXPERIMENTAL SMARTCTL FEATURE] runs a SMART Selective Self Test, to test a range of disk Logical Block Addresses (LBAs), rather than the entire disk. Each range of LBAs that is checked is called a "span" and is specified by a starting LBA (N) and an ending LBA (M) with N less than or equal to M. The range can also be specified as N+SIZE. A span at the end of a disk can be specified by N-max.

For example the commands:

  smartctl -t select,10-20 /dev/hda
  smartctl -t select,10+11 /dev/hda
both runs a self test on one span consisting of LBAs ten to twenty (inclusive). The command:
  smartctl -t select,100000000-max /dev/hda
run a self test from LBA 100000000 up to the end of the disk. The '-t' option can be given up to five times, to test up to five spans. For example the command:
  smartctl -t select,0-100 -t select,1000-2000 /dev/hda
runs a self test on two spans. The first span consists of 101 LBAs and the second span consists of 1001 LBAs. Note that the spans can overlap partially or completely, for example:
  smartctl -t select,0-10 -t select,5-15 -t select,10-20 /dev/hda
The results of the selective self-test can be obtained (both during and after the test) by printing the SMART self-test log, using the '-l selftest' option to smartctl.

Selective self tests are particularly useful as disk capacities increase: an extended self test (smartctl -t long) can take several hours. Selective self-tests are helpful if (based on SYSLOG error messages, previous failed self-tests, or SMART error log entries) you suspect that a disk is having problems at a particular range of Logical Block Addresses (LBAs).

Selective self-tests can be run during normal system operation (unless done in captive mode - see the '-C' option below).

[Note: To use this feature on Linux, the kernel must be compiled with the configuration option CONFIG_IDE_TASKFILE_IO enabled. Please report unusual or incorrect behavior to the smartmontools-support mailing list.]

The following variants of the selective self-test command use spans based on the ranges from past tests already stored on the disk:

select,redo[+SIZE] - [ATA ONLY] [NEW EXPERIMENTAL SMARTCTL FEATURE] redo the last SMART Selective Self Test using the same LBA range. The starting LBA is identical to the LBA used by last test, same for ending LBA unless a new span size is specified by optional +SIZE argument.

For example the commands:

  smartctl -t select,10-20 /dev/hda
  smartctl -t select,redo /dev/hda
  smartctl -t select,redo+20 /dev/hda
have the same effect as:
  smartctl -t select,10-20 /dev/hda
  smartctl -t select,10-20 /dev/hda
  smartctl -t select,10-29 /dev/hda

select,next[+SIZE] - [ATA ONLY] [NEW EXPERIMENTAL SMARTCTL FEATURE] runs a SMART Selective Self Test on the LBA range which follows the range of the last test. The starting LBA is set to (ending LBA +1) of the last test. A new span size may be specified by the optional +SIZE argument.

For example the commands:

  smartctl -t select,0-999 /dev/hda
  smartctl -t select,next /dev/hda
  smartctl -t select,next+2000 /dev/hda
have the same effect as:
  smartctl -t select,0-999 /dev/hda
  smartctl -t select,1000-1999 /dev/hda
  smartctl -t select,2000-3999 /dev/hda

If the last test ended at the last LBA of the disk, the new range starts at LBA 0. The span size of the last span of a disk is adjusted such that the total number of spans to check the full disk will not be changed by future uses of '-t select,next'.

select,cont[+SIZE] - [ATA ONLY] [NEW EXPERIMENTAL SMARTCTL FEATURE] performs a 'redo' (above) if the self test status reports that the last test was aborted by the host. Otherwise it run the 'next' (above) test.

afterselect,on - [ATA ONLY] perform an offline read scan after a Selective Self-test has completed. This option must be used together with one or more of the select,N-M options above. If the LBAs that have been specified in the Selective self-test pass the test with no errors found, then read scan the remainder of the disk. If the device is powered-cycled while this read scan is in progress, the read scan will be automatically resumed after a time specified by the pending timer (see below). The value of this option is preserved between selective self-tests.

afterselect,off - [ATA ONLY] do not read scan the remainder of the disk after a Selective self-test has completed. This option must be use together with one or more of the select,N-M options above. The value of this option is preserved between selective self-tests.

pending,N - [ATA ONLY] set the pending offline read scan timer to N minutes. Here N is an integer in the range from 0 to 65535 inclusive. If the device is powered off during a read scan after a Selective self-test, then resume the test automatically N minutes after power-up. This option must be use together with one or more of the select,N-M options above. The value of this option is preserved between selective self-tests.

scttempint,N[,p] - [ATA ONLY] [NEW EXPERIMENTAL SMARTCTL FEATURE] set the time interval for SCT temperature logging to N minutes. If ',p' is specified, the setting is preserved across power cycles. Otherwise, the setting is volatile and will be reverted to default (1 minute), or last non-volatile setting by the next hard reset. This command also clears the temperature history table. See '-l scttemp' above for more information about SCT temperature logging.

-C, --captive
  Runs self-tests in captive mode. This has no effect with '-t offline' or if the '-t' option is not used. [Note: in the case of SCSI devices, this command option runs the self-test in "Foreground" mode.]

WARNING: Tests run in captive mode may busy out the drive for the length of the test. Only run captive tests on drives without any mounted partitions!

-X, --abort
  Aborts non-captive SMART Self Tests. Note that this command will abort the Offline Immediate Test routine only if your disk has the "Abort Offline collection upon new command" capability.

EXAMPLES

smartctl -a /dev/hda 
Print all SMART information for drive /dev/hda (Primary Master).

smartctl -s off /dev/hdd 
Disable SMART on drive /dev/hdd (Secondary Slave).

smartctl --smart=on --offlineauto=on --saveauto=on /dev/hda 
Enable SMART on drive /dev/hda, enable automatic offline testing every four hours, and enable autosaving of SMART Attributes. This is a good start-up line for your system's init files. You can issue this command on a running system.

smartctl -t long /dev/hdc 
Begin an extended self-test of drive /dev/hdc. You can issue this command on a running system. The results can be seen in the self-test log visible with the '-l selftest' option after it has completed.

smartctl -s on -t offline /dev/hda 
Enable SMART on the disk, and begin an immediate offline test of drive /dev/hda. You can issue this command on a running system. The results are only used to update the SMART Attributes, visible with the '-A' option. If any device errors occur, they are logged to the SMART error log, which can be seen with the '-l error' option.

smartctl -A -v 9,minutes /dev/hda 
Shows the vendor Attributes, when the disk stores its power-on time internally in minutes rather than hours.

smartctl -q errorsonly -H -l selftest /dev/hda 
Produces output only if the device returns failing SMART status, or if some of the logged self-tests ended with errors.

smartctl -q silent -a /dev/hda 
Examine all SMART data for device /dev/hda, but produce no printed output. You must use the exit status (the $? shell variable) to learn if any Attributes are out of bound, if the SMART status is failing, if there are errors recorded in the self-test log, or if there are errors recorded in the disk error log.

smartctl -a -d 3ware,0 /dev/sda 
Examine all SMART data for the first ATA disk connected to a 3ware RAID controller card.

smartctl -a -d 3ware,0 /dev/twe0 
Examine all SMART data for the first ATA disk connected to a 3ware RAID 6000/7000/8000 controller card.

smartctl -a -d 3ware,0 /dev/twa0 
Examine all SMART data for the first ATA disk connected to a 3ware RAID 9000 controller card.

smartctl -t short -d 3ware,3 /dev/sdb 
Start a short self-test on the fourth ATA disk connected to the 3ware RAID controller card which is the second SCSI device /dev/sdb.

smartctl -a -d hpt,1/3 /dev/sda 
Examine all SMART data for the (S)ATA disk directly connected to the third channel of the first HighPoint RocketRAID controller card.

smartctl -t short -d hpt,1/1/2 /dev/sda

Start a short self-test on the (S)ATA disk connected to second pmport on the first channel of the first HighPoint RocketRAID controller card.

smartctl -t select,10-100 -t select,30-300 -t afterselect,on -t pending,45 /dev/hda 
Run a selective self-test on LBAs 10 to 100 and 30 to 300. After the these LBAs have been tested, read-scan the remainder of the disk. If the disk is power-cycled during the read-scan, resume the scan 45 minutes after power to the device is restored.

smartctl -a -d cciss,0 /dev/cciss/c0d0 
Examine all SMART data for the first SCSI disk connected to a cciss RAID controller card.

RETURN VALUES

The return values of smartctl are defined by a bitmask. If all is well with the disk, the return value (exit status) of smartctl is 0 (all bits turned off). If a problem occurs, or an error, potential error, or fault is detected, then a non-zero status is returned. In this case, the eight different bits in the return value have the following meanings for ATA disks; some of these values may also be returned for SCSI disks.
TagDescription
Bit 0: Command line did not parse.
Bit 1: Device open failed, or device did not return an IDENTIFY DEVICE structure.
Bit 2: Some SMART command to the disk failed, or there was a checksum error in a SMART data structure (see '-b' option above).
Bit 3: SMART status check returned "DISK FAILING".
Bit 4: We found prefail Attributes <= threshold.
Bit 5: SMART status check returned "DISK OK" but we found that some (usage or prefail) Attributes have been <= threshold at some time in the past.
Bit 6: The device error log contains records of errors.
Bit 7: The device self-test log contains records of errors.

To test within the shell for whether or not the different bits are turned on or off, you can use the following type of construction (this is bash syntax):

smartstat=$(($? & 8)) 
This looks at only at bit 3 of the exit status $? (since 8=2^3). The shell variable $smartstat will be nonzero if SMART status check returned "disk failing" and zero otherwise.

NOTES

The TapeAlert log page flags are cleared for the initiator when the page is read. This means that each alert condition is reported only once by smartctl for each initiator for each activation of the condition.

AUTHOR

Bruce Allen smartmontools-support@lists.sourceforge.net University of Wisconsin - Milwaukee Physics Department

CONTRIBUTORS

The following have made large contributions to smartmontools:
Casper Dik (Solaris SCSI interface)
Christian Franke (Windows interface and Cygwin package)
Douglas Gilbert (SCSI subsystem)
Guido Guenther (Autoconf/Automake packaging)
Geoffrey Keating (Darwin ATA interface)
Eduard Martinescu (FreeBSD interface)
Frédéric L. W. Meunier (Web site and Mailing list)
Keiji Sawada (Solaris ATA interface)
Sergey Svishchev (NetBSD interface)
David Snyder and Sergey Svishchev (OpenBSD interface)
Phil Williams (User interface and drive database)
Yuri Dario (OS/2, eComStation interface)
Shengfeng Zhou (Linux Highpoint RocketRaid interface)
Many other individuals have made smaller contributions and corrections.

CREDITS

This code was derived from the smartsuite package, written by Michael Cornwell, and from the previous UCSC smartsuite package. It extends these to cover ATA-5 disks. This code was originally developed as a Senior Thesis by Michael Cornwell at the Concurrent Systems Laboratory (now part of the Storage Systems Research Center), Jack Baskin School of Engineering, University of California, Santa Cruz. http://ssrc.soe.ucsc.edu/ .

HOME PAGE FOR SMARTMONTOOLS: Please see the following web site for updates, further documentation, bug reports and patches: http://smartmontools.sourceforge.net/

SEE ALSO: smartd(8), badblocks(8), ide-smart(8).

REFERENCES FOR SMART An introductory article about smartmontools is Monitoring Hard Disks with SMART, by Bruce Allen, Linux Journal, January 2004, pages 74-77. This is http://www.linuxjournal.com/article.php?sid=6983 online.

If you would like to understand better how SMART works, and what it does, a good place to start is with Sections 4.8 and 6.54 of the first volume of the 'AT Attachment with Packet Interface-7' (ATA/ATAPI-7) specification. This documents the SMART functionality which the smartmontools utilities provide access to. You can find Revision 4b of this document at http://www.t13.org/docs2004/d1532v1r4b-ATA-ATAPI-7.pdf . Earlier and later versions of this Specification are available from the T13 web site http://www.t13.org/ .

The functioning of SMART was originally defined by the SFF-8035i revision 2 and the SFF-8055i revision 1.4 specifications. These are publications of the Small Form Factors (SFF) Committee. Links to these documents may be found in the References section of the smartmontools home page at http://smartmontools.sourceforge.net/ .

CVS ID OF THIS PAGE: $Id: smartctl.8.in,v 1.105 2008/03/04 22:09:47 ballen4705 Exp $
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