program is an interactive file system debugger. It can be used to
examine and change the state of an ext2 file system.
is the special file corresponding to the device containing the ext2
file system (e.g /dev/hdXX).
Tag | Description |
-w |
Specifies that the file system should be opened in read-write mode.
Without this option, the file system is opened in read-only mode.
|
-c |
Specifies that the file system should be opened in catastrophic mode, in
which the inode and group bitmaps are not read initially. This can be
useful for filesystems with significant corruption, but because of this,
catastrophic mode forces the filesystem to be opened read-only.
|
-i |
Specifies that
device represents an ext2 image file created by the
e2image program. Since the ext2 image file only contains the superblock, block
group descriptor, block and inode allocation bitmaps, and
the inode table, many
debugfs commands will not function properly.
Warning: no safety checks are in place, and
debugfs may fail in interesting ways if commands such as
ls, dump, etc. are tried without specifying the
data_source_device using the
-d option.
debugfs is a debugging tool. It has rough edges!
|
-d data_source_device |
|
Used with the
-i option, specifies that
data_source_device should be used when reading blocks not found in the ext2 image file.
This includes data, directory, and indirect blocks.
|
-b blocksize |
|
Forces the use of the given block size for the file system, rather than
detecting the correct block size as normal.
|
-s superblock |
|
Causes the file system superblock to be read from the given block number,
rather than the default (1). If you give a
-s option, you must also give a
-b option.
|
-f cmd_file |
|
Causes
debugfs to read in commands from
cmd_file, and execute them. When
debugfs is finished executing those commands, it will exit.
|
-R request |
|
Causes
debugfs to execute the single command
request, and then exit.
|
-V |
print the version number of
debugfs and exit.
|
as an argument to specify an inode (as opposed to a pathname)
in the filesystem which is currently opened by
. The
argument may be specified in two forms. The first form is an inode
number surrounded by angle brackets, e.g.,
. The second form is a pathname; if the pathname is prefixed by a forward slash
(/), then it is interpreted relative to the root of the filesystem
which is currently opened by
. If not, the pathname is
interpreted relative to the current working directory as maintained by
. This may be modified by using the
.
supports.
Tag | Description |
bmap filespec logical_block |
|
Print the physical block number corresponding to the logical block number
logical_block in the inode
filespec. |
cat filespec |
|
Dump the contents of the inode
filespec to stdout.
|
cd filespec |
|
Change the current working directory to
filespec. |
chroot filespec |
|
Change the root directory to be the directory
filespec. |
close |
Close the currently open file system.
|
clri file |
|
Clear the contents of the inode
file. |
dump [-p] filspec out_file |
|
Dump the contents of the inode
filespec to the output file
out_file. If the
-p option is given set the owner, group and permissions information on
out_file to match
filespec. |
expand_dir filespec |
|
Expand the directory
filespec. |
feature [fs_feature] [-fs_feature] ... |
|
Set or clear various filesystem features in the superblock. After setting
or clearing any filesystem features that were requested, print the current
state of the filesystem feature set.
|
find_free_block [count [goal]] |
|
Find the first
count free blocks, starting from
goal and allocate it.
|
find_free_inode [dir [mode]] |
|
Find a free inode and allocate it. If present,
dir specifies the inode number of the directory
which the inode is to be located. The second
optional argument
mode specifies the permissions of the new inode. (If the directory bit is set
on the mode, the allocation routine will function differently.)
|
freeb block [count] |
|
Mark the block number
block as not allocated.
If the optional argument
count is present, then
count blocks starting at block number
block will be marked as not allocated.
|
freei filespec |
|
Free the inode specified by
filespec. |
help |
Print a list of commands understood by
debugfs(8).
|
icheck block ... |
|
Print a listing of the inodes which use the one or more blocks specified
on the command line.
|
imap filespec |
|
Print the location of the inode data structure (in the inode table)
of the inode
filespec. |
init_filesys device blocksize |
|
Create an ext2 file system on
device with device size
blocksize. Note that this does not fully initialize all of the data structures;
to do this, use the
mke2fs(8)
program. This is just a call to the low-level library, which sets up
the superblock and block descriptors.
|
kill_file filespec |
|
Deallocate the inode
filespec and its blocks. Note that this does not remove any directory
entries (if any) to this inode. See the
rm(1)
command if you wish to unlink a file.
|
lcd directory |
|
Change the current working directory of the
debugfs process to
directory on the native filesystem.
|
ln filespec dest_file |
|
Create a link named
dest_file which is a link to
filespec. Note this does not adjust the inode reference counts.
|
logdump [-acs] [-b<block>] [-i<filespec>] [-f<journal_file>] [output_file] |
|
Dump the contents of the ext3 journal. By default, the journal inode as
specified in the superblock. However, this can be overridden with the
-i option, which uses an inode specifier to specify the journal to be
used. A file containing journal data can be specified using the
-f option. Finally, the
-s option utilizes the backup information in the superblock to locate the
journal.
|
|
The
-a option causes the
logdump program to print the contents of all of the descriptor blocks.
The
-b option causes
logdump to print all journal records that are refer to the specified block.
The
-c option will print out the contents of all of the data blocks selected by
the
-a and
-b options.
|
ls [-l] [-d] filespec |
|
Print a listing of the files in the directory
filespec. The
-l flag will list files using a more verbose format.
The
-d flag will list deleted entries in the directory.
|
modify_inode filespec |
|
Modify the contents of the inode structure in the inode
filespec. |
mkdir filespec |
|
Make a directory.
|
mknod filespec [p|[[c|b] major minor]] |
|
Create a special device file (a named pipe, character or block device).
If a character or block device is to be made, the
major and
minor device numbers must be specified.
|
ncheck inode_num ... |
|
Take the requested list of inode numbers, and print a listing of pathnames
to those inodes.
|
open [-w] [-e] [-f] [-i] [-c] [-b blocksize] [-s superblock] device |
|
Open a filesystem for editing. The
-f flag forces the filesystem to be opened even if there are some unknown
or incompatible filesystem features which would normally
prevent the filesystem from being opened. The
-e flag causes the filesystem to be opened in exclusive mode. The
-b, -c, -i, -s, and -w options behave the same as the command-line options to
debugfs. |
pwd |
Print the current working directory.
|
quit |
Quit
debugfs |
rdump directory destination |
|
Recursively dump
directory and all its contents (including regular files, symbolic links, and other
directories) into the named
destination which should be an existing directory on the native filesystem.
|
rm pathname |
|
Unlink
pathname. If this causes the inode pointed to by
pathname to have no other references, deallocate the file. This command functions
as the unlink() system call.
|
rmdir filespec |
|
Remove the directory
filespec. |
setb block [count] |
|
Mark the block number
block as allocated.
If the optional argument
count is present, then
count blocks starting at block number
block will be marked as allocated.
|
seti filespec |
|
Mark inode
filespec as in use in the inode bitmap.
|
set_inode_field filespec field value |
|
Modify the inode specified by
filespec so that the inode field
field has value
value. The list of valid inode fields which can be set via this command
can be displayed by using the command:
set_inode_field -l |
set_super_value field value |
|
Set the superblock field
field to
value. The list of valid superblock fields which can be set via this command
can be displayed by using the command:
set_super_value -l |
show_super_stats [-h] |
|
List the contents of the super block and the block group descriptors. If the
-h flag is given, only print out the superblock contents.
|
stat filespec |
|
Display the contents of the inode structure of the inode
filespec. |
testb block [count] |
|
Test if the block number
block is marked as allocated in the block bitmap.
If the optional argument
count is present, then
count blocks starting at block number
block will be tested.
|
testi filespec |
|
Test if the inode
filespec is marked as allocated in the inode bitmap.
|
unlink pathname |
|
Remove the link specified by
pathname to an inode. Note this does not adjust the inode reference counts.
|
write source_file out_file |
|
Create a file in the filesystem named
out_file, and copy the contents of
source_file into the destination file.
|
>.