How to know if a disk is an SSD or an HDD

Question

I want to know whether a disk is a solid-state drive or hard disk.

lshw is not installed. I do yum install lshw and it says there is no package named lshw. I do not know which version of http://pkgs.repoforge.org/lshw/ is suitable for my CentOS.

I search the net and there is nothing that explain how to know whether a drive is SSD or HDD. Should I just format them first?

Result of fdisk -l:

Disk /dev/sda: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00074f7d

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          14      103424   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              14         536     4194304   82  Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3             536       14594   112921600   83  Linux

Disk /dev/sdc: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/sdb: 128.0 GB, 128035676160 bytes
255 heads, 63 sectors/track, 15566 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/sdd: 480.1 GB, 480103981056 bytes
255 heads, 63 sectors/track, 58369 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

If this really is a SSD you might want to reformat it to align the erase blocks with the partitions. — symcbean, Feb 21 '13 at 13:58
SATA (Serial ATA) refers to the connection type of the drive, and does not imply that it is a Hard Disk Drive (HDD). SSDs can simultaneously be SATA, so I'm suggesting an edit to the title. — SpellingD, Feb 21 '13 at 17:10
Nowadays, the output of fdisk -l also includes a Disk model line for each physical disk, where SSD disks typically have the string SSD in their model name which appears there (at least on my system, and otherwise you could search the Internet for the model). But other answers below are perhaps more robust. — matanox, Jun 06 '21 at 17:55

Totor · Accepted Answer · 2021-02-18T22:39:52.860

456

Linux automatically detects SSD, and since kernel version 2.6.29, you may verify sda with:

cat /sys/block/sda/queue/rotational

You should get 1 for hard disks and 0 for a SSD.

It will probably not work if your disk is a logical device emulated by hardware (like a RAID controller).

See this answer for more information about SSD partitioning, filesystem...

edited Feb 18 '21 at 22:39

answered Feb 21 '13 at 09:48

Totor

20,040

2

On Stackoverflow somebody found this sys-info didn't work. – PythoNic Jul 23 '14 at 10:55
@PythoNic please file a kernel bug report about this. – Totor Sep 04 '14 at 12:58
1

@totor Better add this comment on the other post. I don't know his/her kernel version :) – PythoNic Sep 04 '14 at 13:21
Nice! Works without having sudo privileges. – haridsv Sep 02 '15 at 10:58
The method does not work for USB sticks – they are certainly not rotational drives (see Doesn't detect USB flash drive as SSD). – dma_k Oct 20 '15 at 10:44
What about hybrid drives? – CMCDragonkai Nov 01 '15 at 10:35
@CMCDragonkai They propably appear as rotational since the flash memory is mostly an "improved cache". You tell us... – Totor Mar 28 '16 at 20:42
4

@Totor You are correct in the "hybrid" drives. However, dual-drive hybrids show up as two individual drives, where SSHD (Solid-State Hybrid Drive) shows up as a single drive. So, the SSHD would show rotational of 1. – Terrance Jun 30 '16 at 16:18
8

On virtual servers, you may need to fetch /sys/block/vda/queue/rotational – MonoThreaded Nov 08 '16 at 21:45
On certain computers, you need to run cat /sys/block/nvme0n1/queue/rotational instead, sda does not exist on my laptop – Ferrybig Dec 24 '18 at 10:33
2

@Ferrybig There are only SSDs in NVME format, not HDDs (unless you do have some strange breakout adapter from NVME slot to plain SATA cable). But not sure if even SATA SSD over NVME shows as NVME in linux or as plain sdX. – Marki555 Dec 03 '19 at 09:20
This works if you know which device to show (e.g. sda) a-priori. If you want to discover disks + whether they are rotational, try @don_crissti answer. – arielf Jan 28 '20 at 16:10
This didn't work for me, both the hd and the ssd show 1 – spacebiker Jan 20 '21 at 20:03
This work for me, i got 0, my disk is SSD. – Gedeon Mutshipayi Jul 16 '22 at 09:18
On all raids it will show as 0 aswell.. i think unknown is 0 – cyford Feb 08 '24 at 19:18

don_crissti · Answer 2 · 2022-12-07T00:35:41.517

187

With lsblk (part of the util-linux package):

lsblk -d -o name,rota

NAME ROTA
sda     0
sdb     0
sdc     1

where ROTA means rotational device (1 if true, 0 if false).

Note that, as mentioned in the comments, some USB controllers don't correctly report this rotational attribute, a possible fix being the use of an explicit UDEV rule.

Also, more recent versions of lsblk support the -I,--include and -e,--exclude options that allow filtering devices by major number and also support JSON output so e.g. to show only the name and serial number of non-loop devices that are non-rotational you could run:

lsblk -e 7 -do name,serial,rota --json | \
jq -r '.blockdevices[] | select(.rota==false) | [.name,.serial] | @tsv'

edited Dec 07 '22 at 00:35

answered Sep 04 '15 at 11:02

don_crissti

82,805

3

That utility seems to report the same information as in /sys/block/.../rotational. – dma_k Oct 20 '15 at 10:45
@dma_k Little wonder, considering it appears to use that one. Try it yourself: strace lsblk -d -o name,rota /dev/sda 2>&1 | grep --context=3 --color rotational – user May 13 '16 at 16:30
5

Actually I was looking into various ways because some USB controllers don't tell that drive is actually non-rotational (for example, USB flash) and there is no way in Linux to tell the truth. At the end of the day I have fixed that by creating the explicit rule in /etc/udev/rules.d/90-non-rotational.rules: ACTION=="add|change", SUBSYSTEMS=="usb", ENV{ID_SERIAL}=="SanDisk_Ultra_Fit_*-0:0", ATTR{queue/rotational}="0", ATTR{queue/scheduler}="deadline" – dma_k Jun 08 '16 at 18:01
1

lsblk reports "0" for all my good old SATA spinning HDDs here (ASROCK mobo). « some USB controllers don't tell that drive is actually non-rotational (for example, USB flash) » @dma_k this is so true --and better this way than the other way for USB wired external spinning HDDs IMHA. – tuk0z Sep 14 '16 at 20:45
this one is better than https://unix.stackexchange.com/posts/65602/revisions because it lists all devices – crysman Dec 18 '19 at 12:32
4

This works best for me, but it includes redundant/unwanted loop devices (e.g. due to Ubuntu snaps). A slight improvement is: lsblk -d -e 7 -o NAME,ROTA,DISC-MAX,MODEL which excludes loop devices + adds the model name (manufacturer) and disk capacity. – arielf Jan 28 '20 at 16:01

score 63 · Answer 3 · edited Sep 03 '18 at 04:31

63

Use smartctl (install by installing smartmontools) to retrieve vendor information,

sudo smartctl -a /dev/sdb

If you see a line like this,

Rotation Rate: Solid State Device

That would be a SSD drive.

edited Sep 03 '18 at 04:31

zrajm

894

answered Feb 21 '13 at 09:07

daisy

54,555

score 44 · Answer 4 · edited Mar 01 '22 at 14:09

44

I needed to do this on the VPS and none of the provided solutions worked for me, but this answer did the trick:

https://serverfault.com/questions/551453/how-do-i-verify-that-my-hosting-provider-gave-me-ssds/551495#551495

This just reads random data from the drive and assesses the time.

time for i in `seq 1 1000`; do
    dd bs=4k if=/dev/sda count=1 skip=$(( $RANDOM * 128 )) >/dev/null 2>&1;
done

NOTE: You may need sudo before the dd command, depending on your permissions.

Here are my results for an SSD:

real    0m1.375s
user    0m0.285s
sys     0m0.944s

And a HDD:

real    0m14.249s
user    0m0.752s
sys     0m6.284s

As you can see, the HDD takes about 10x the duration. This may not be reliable for some very fast HDD's, but in general, it will give you a good idea.

edited Mar 01 '22 at 14:09

Addison

105
4

answered Jan 08 '16 at 14:38

dav

541

1

I have a non-ssd, RAID10, and my results are: real 0m1.351s - user: 0m0.307s - sys: 0m0.560s – the_nuts Apr 10 '16 at 10:48
5

This is a good answer and it does work across the board. The thing is some HDDs are quite fast and the results can be similar to those of SSDs. Still, this answer provides a good metric. – itoctopus Jun 10 '16 at 04:57
1

On my VPS without an SSD this provides results like your SSD example. I believe this may be fooled by "hybrid" (SSD cached HDD) setups. – trr Aug 16 '16 at 01:40
doesn't work for me. I find SSD and HDD produce similar result. – qqibrow Oct 03 '18 at 20:46
1

On a VPS hardware's virtualized. You can't really tell if your files are stored on a HDD, cached, or stored on a SSD. – vidarlo Feb 09 '19 at 22:45

score 18 · Answer 5 · answered Sep 04 '15 at 13:25

18

The other answers already tell you how to get this information in a number of ways , including /proc. But you must expect all these mechanisms to lie if there's any virtualisation in the way, such as a hybrid SAN array with multiple tiers, or if the Linux machine is a virtual machine (where Linux will probably report the disk as a basic SCSI rotating disk, regardless of what the hardware really is)

answered Sep 04 '15 at 13:25

Tim Cutts

446

this may be one of the more important responses... and also within the BIOS, or EFI/UEFI one may need to set the SATA controller mode to AHCI and then also mark each disk as SSD within the bios. My Asrock board on home pc is like this, can't remember if there was a similiar thing on server boards (supermicro) I have at work but i don't use SSD at work. – ron Aug 16 '18 at 17:50
@ron - What do you mean by setting the SATA controller mode to AHCI? How does it affect the ability to accurately report if the device is a SSD or not? – Motivated Dec 28 '18 at 05:03
look up AHCI vs IDE, wording from first web search: IDE is considered adequate for the average computer user, and is the most compatible with other technology, particularly older devices. However, it lacks support for new technologies...AHCI provides a standard system that designers and developers can use to configure, detect, or program SATA/AHCI adapters.* – ron Jan 03 '19 at 22:29
that is a basic settings in the BIOS, somewhere under Storage, the choices are IDE, AHCI, and also depending on make/model/year of motherboard can also offer RAID. SSD's came out long after IDE basically went obsolete and the standard became AHCI, For example installing Windows95 on a computer today it would not recognize any hardware... being in IDE mode certainly would not help communication with a SSD not so much accuracy but simply being able to communicate with a SATA controller which is based on AHCI protocols. – ron Jan 03 '19 at 22:33

score 12 · Answer 6 · answered Feb 21 '13 at 09:01

12

check cat /proc/scsi/scsi. there you should see the exact model of your disk. then you just google the model to find info about it.

answered Feb 21 '13 at 09:01

replay

8,553
1
27
31

3

dmesg will contain the same info. dmesg | grep -i -e scsi -e ata – Matt Feb 21 '13 at 09:41

score 5 · Answer 7 · edited Jun 29 '16 at 12:33

5

This is an old post but I wanted to share another way to do this which I found out by accident:

sg_vpd --page=bdc /dev/sda

This commands fetches the Vital Product Data for the block device characteristics. For a rotating head disk, the output will include: Nominal rotation rate: 7200 rpm For an SSD, it will include: Non-rotating medium (e.g. solid state)

edited Jun 29 '16 at 12:33

Jenny D

13,172

answered Jun 29 '16 at 12:13

user177312

51

1

+1. nice, but running that on my (aging and soon to be replaced) WD Greens says Medium rotation rate is not reported. hdparm and smartmonctl say the same. I guess WD don't want to tell. – cas Aug 04 '16 at 13:41
sg_vpd -i might be more useful, at least it gives vendor info on from the drive. Doesn't work on a raid, tho'. – Dale Jan 11 '19 at 16:30

score 2 · Answer 8 · edited Dec 15 '19 at 17:12

2

Type this in your Linux terminal:

cat /proc/scsi/scsi

Like mine:

$ cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: ATA      Model: ST1000LM024 HN-M Rev: 0004
  Type:   Direct-Access                    ANSI  SCSI revision: 05
Host: scsi1 Channel: 00 Id: 00 Lun: 00
  Vendor: ATA      Model: SAMSUNG SSD PM83 Rev: 3D1Q
  Type:   Direct-Access                    ANSI  SCSI revision: 05
Host: scsi2 Channel: 00 Id: 00 Lun: 00
  Vendor: HL-DT-ST Model: DVD+-RW GT80N    Rev: A103
  Type:   CD-ROM                           ANSI  SCSI revision: 05

You can see the model of your hard drive if it is SSD or HHD.

edited Dec 15 '19 at 17:12

Eliah Kagan

4,155

answered Dec 15 '19 at 13:39

user386433

21

This seems to show only ATA/SCSI block-devices, others such as NVMe SSDs do not show. – arielf Jan 27 '20 at 22:36
if your disk is behind a raid controller, you will only see the raid controller such as Vendor: LSI Model: SMC3108 Rev: 4.27 – ron Jan 28 '20 at 22:01

score 2 · Answer 9 · edited Jan 29 '20 at 13:14

2

find /sys/block/* -maxdepth 1 -exec echo {} \; -exec grep '0' {}/queue/rotational \; | grep -B1 '^0' | grep '^/' | sed 's/^.*\///g'

This searches all block devices and check to see if it is rotary (1); if not (0) it is ssd.

This only displays discs marked as ssd.

edited Jan 29 '20 at 13:14

Jeff Schaller

67,283
35
116
255

answered Jan 15 '20 at 14:41

user515185

21

ajouté | grep -v 'loop' dans la commande pour ignorer les "block device" virtuel
ex: for SsDrive in $(find /sys/block/* -maxdepth 1 -exec echo {} ; -exec grep '0' {}/queue/rotational ; | grep -v 'loop' | grep -B1 '^0' | grep '^/' | sed 's/^.*///g') ; do find /dev/ -name $SsDrive[0-9] ; done – user515185 Jan 28 '20 at 21:50
I noticed after my translation yesterday that you've previously rolled back attempted translations. Please note that answers on this site should be in English. Thank you! – Jeff Schaller Jan 30 '20 at 17:56
Add | grep -v 'loop' on the command line to forget the loop (virtual block device ) ex: for SsDrive in $(find /sys/block/* -maxdepth 1 -exec echo {} ; -exec grep '0' {}/queue/rotational ; | grep -v 'loop' | grep -B1 '^0' | grep '^/' | sed 's/^.*///g') ; do find /dev/ -name $SsDrive[0-9] ; done – user515185 Jan 30 '20 at 21:20

score -1 · Answer 10 · answered Sep 12 '21 at 09:49

-1

If you want to be lazy and realy want to read something like ssd or hdd give

sudo lshw -short -C disk

a try.

My Output shows both:

H/W path         Device      Class          Description
=======================================================
/0/100/17/0      /dev/sda    disk           1TB TOSHIBA MQ01ABD1
/0/100/17/1      /dev/sdb    disk           128GB SSD PHISON 128GB
/0/100/17/0.0.0  /dev/sr0    disk           DVDRAM GUD0N

answered Sep 12 '21 at 09:49

John Goofy

931

Description does not always include "HDD" or "SSD". – gavv Feb 19 '22 at 11:31
@gavv hm, it's strange ... the 'lshw' is may be the best utility that gives the most detailed info about the hardware on a system. but it doesn't tell the type of the disk! may be it is time to upgrade the 'lshw' to a new version. :) – ccsann Aug 09 '22 at 11:23

How to know if a disk is an SSD or an HDD

10 Answers10

Linked

Related