Check if Hard Drive is SSD or HDD on Linux

To determine whether our file system uses SSD or HDD technology, we need to identify which type of storage device is used by our Linux system. Understanding storage hardware helps optimize performance and make informed decisions about data placement.

There are many different aspects of Linux storage with numerous tools available for reading and configuring storage devices. We use terms like "drive", "volume", and "mount point" to describe hard drives, optical discs, and USB sticks. To understand the underlying technology, we focus on two key aspects

• What physical disk or block device we are examining (using df)

• The hardware parameters of that disk (using hdparm)

Identifying the Physical Disk

We start by checking disk usage with the "disk free" command to identify which physical devices contain our file systems.

$ df -Th -x tmpfs

Filesystem                   Type     Size  Used Avail Use% Mounted on
/dev/sdb2                    ext4     228G  173G   44G  80% /
/dev/sdb1                    vfat     511M  6.3M  505M   2% /boot/efi
/dev/sdc1                    fuseblk  466G  352G  114G  76% /media/a/9EE8E134E8E10AFB
/dev/mapper/wonder--vg-root  ext4     902G   57G  799G   7% /media/a/450c0236-eea5-4a7

The command options used are

• -T Shows the file system type

• -h Displays sizes in human-readable format

• -x tmpfs Excludes temporary file systems from output

From this output, we identify that our root filesystem is on /dev/sdb2, and we can see other physical devices like sdc and logical volumes under mapper.

Using hdparm to Check Drive Type

The Hard Disk Parameters command (hdparm) can read detailed information from storage drives. It must be run as root since it accesses hardware directly.

Checking SSD Drives

To examine the hardware behind our root filesystem on /dev/sdb, we use the -I option for detailed information

$ sudo hdparm -I /dev/sdb

/dev/sdb:
ATA device, with non-removable media
Model Number:       Samsung SSD 840 EVO 250GB

The model name clearly contains "SSD", indicating this is a Solid State Drive.

Using Nominal Media Rotation Rate

For drives with less obvious naming, we can check the Nominal Media Rotation Rate field

$ sudo hdparm -I /dev/sdc | grep 'Nominal Media Rotation Rate'

    Nominal Media Rotation Rate: Solid State Device

When the output shows "Solid State Device", it confirms this is an SSD with no moving parts.

Identifying HDD Drives

For traditional hard disk drives, the rotation rate shows as a numeric value

$ sudo hdparm -I /dev/mapper/wonder--vg-root | grep 'Nominal Media Rotation Rate'

    Nominal Media Rotation Rate: 7200

This indicates a mechanical hard drive spinning at 7200 revolutions per minute (RPM).

Key Differences

Alternative Methods

You can also use these commands to identify drive types

# Check rotation rate directly
$ cat /sys/block/sda/queue/rotational

# List all block devices with rotation info
$ lsblk -d -o name,rota

A value of 1 indicates rotational (HDD), while 0 indicates non-rotational (SSD).

Conclusion

Linux provides multiple methods to identify storage device types. The most reliable approach combines df to identify physical devices and hdparm -I to examine hardware parameters. The Nominal Media Rotation Rate field definitively distinguishes between SSDs (showing "Solid State Device") and HDDs (showing RPM values).