How to Check SMART Status on Mac Hard Drives

May 31, 2018 - 30 Comments

How to check SMART status of Mac hard disk drives

Mac users can easily check the SMART status of their hard drives and internal disk storage by using Disk Utility in Mac OS, offering a simple way to see if the disk hardware itself is in good health or is experiencing a hardware issue.

This article will walk you through how to check SMART status on hard disks in Mac OS, and it works with both SSD and HDD volumes. Checking SMART status of a drive can give you actionable information about whether a disk is about to fail and therefore is in need of an urgent data backup and drive replacement.

SMART, which stands for Self Monitoring Analysis and Reporting Technology System, is a mechanism for reporting disk health or disk problems to the operating system, and SMART status can tell you if a drive is failing or has some other fatal error to the actual disk hardware, providing a very clear indicator that it’s time to urgently backup all important data and then replace the failing drive.

As you can imagine, SMART status of a disk is quite important, and if you want to know whether a disk is about to fail then checking SMART status is perhaps one of the simplest and easiest ways to know.

How to Check SMART Status of Disk Drives on Mac OS

This trick works the same on all modern versions of MacOS and Mac OS System software with the Disk Utility application. Here’s how it works:

  1. Open “Disk Utility” on the Mac, Disk Utility is found in the /Applications/Utilities/ folder
  2. How to check SMART status of Mac hard disk drives with Disk Utility

  3. Select the disk from the list at the left of the Disk Utility screen (select the actual main disk, not a partition)*
  4. Look for the “S.M.A.R.T. Status” of the disk information overview in Disk Utility
    • If the SMART Status says “Verified” the drive is in good health
    • If S.M.A.R.T. Status says “Failing” the drive urgently needs to be backed up and replaced **
    • If you see any message stating the disk has a fatal hardware error or problem, the drive is also going to fail soon and needs to be backed up and replaced ASAP

    Check SMART Status of Mac Hard Drive

  5. Exit out of Disk Utility when finished

A SMART Status of “Failing” or any hardware error message is an urgent problem because the disk drive will soon cease to function entirely, leading to permanent data loss.

It’s a good habit to routinely backup a Mac with Time Machine or another backup option anyway, but it’s extra important to immediately backup if you see any failing message pertaining to SMART Status or any other fatal error in the Disk Utility app.

You can also run First Aid and verify and repair drives in Disk Utility on the Mac, but issues that are repairable by Disk Utility are almost never SMART failures or any other hardware problem.

SMART Status reports no errors, but the disk is having a problem

If you are experiencing strange disk issues but the SMART Status reports as “Verified” with no error messages, then you can try and verify and repair the disk with Disk Utility from Recovery mode, or with fsck from Single User Mode or the Recovery mode Terminal.

Having a routine of checking, verifying, and repairing a disk, as well as backing up the Mac, are good general Mac maintenance tips that should be followed anyway.

Help, I can’t see my disk / drive in Disk Utility at all!

If the disk or drive is not showing up in Disk Utility at all, and you’re looking at Disk Utility from another volume or boot drive, that suggests either one of the following: the drive has already failed, is periodically failing and will soon completely fail, or at best the disk is somehow not connected physically (highly unlikely but vaguely possible that an internal connection came loose).

Note that not all external drives and external disk enclosures include support for SMART status, so some volumes may not report any SMART finding or information.

* The actual disk drives usually have a name that is related to the manufacturer of the disk itself. For the example, “APPLE SSD SM0512G Media” would be the drive, whereas “Macintosh HD” would be a partition on that drive, thus you’d want to select the “APPLE SSD SM0512G” option rather than any partition.

** The simplest way to back up a Mac hard drive is with Time Machine. It is absolutely critical to backup a failing disk, as not doing so can and will result in permanent data loss. If you are not sure what to do, contact an authorized Apple Support center or official Apple Support. A failing disk is a hardware problem and indicates the drive itself must be replaced with a new disk.

Do you know of any other helpful tips for checking SMART status, or examining hard drive issues or checking for an impending disk failure in Mac OS? Share your own tools, tips, and experiences in the comments below!


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Posted by: Paul Horowitz in Mac OS, Tips & Tricks, Troubleshooting


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  1. Majikthize says:

    macOS DOES, indeed, support SMART reporting from external drives, specifically my LaCie 5big and 2big Thunderbolt 2 enclosures. Many USB enclosures do not pass through SMART data, and I’ve read the macOS does not support even those that do.

  2. Motti Shneor says:

    This Article isn’t particularly helpful because:
    1. For Internal drives (especially the boot drive) MacOS itself will warn you when SMART status of a drive becomes “failing” – you won’t need to get to “Disk Utility” for that.
    2. The way-too-general SMART status presented by Disk Utility (a single word) tells you very little about what is going on with the drive – other utilities (e.g. “SMART Utility”) gives you much more than that.
    3. In way too many occurrences “Disk Utility” presents a “Not supported” in its “S.M.A.R.T Status” and leaves you with no indication at all about a drive. For some reason (I believe a good one…) SMART status is not available for ANY external drive – which is usually what I’d like to check regularly – backup drives and long-term storage drives are very important to check because if they fail – you lose your very-important backups and Media.

    • Majikthize says:

      “SMART status is not available for ANY external drive”

      Wrong. It doesn’t work with most, perhaps all, USB drives. It works fine with my Thunderbolt 2 drives.

  3. David Jones says:

    Apple do not support SMART for external drives at all. This is officially confirmed by Apple support and accurate as of Catalina. Big Sur is also unlikely to support it.

    Currently, the only way to get SMART working for external drives is to use a third party tool, that will install support (eg TechTools, DriveDX or Disk Warrior, to name but a few) or to use the open source driver OS-X-SAT-SMART-Driver. However, not all external SATA controllers are supported. So, do your research before buying an external enclosure. Or, buy a NAS and let one of the NAS OEMs handle it for you.

    • Majikthize says:

      “Apple do not support SMART for external drives at all.”

      Wrong. It doesn’t work with most, perhaps all, USB drives. It works fine with my Thunderbolt 2 drives.

  4. JohnIL says:

    Sometimes Disk Utility only displays the Mac OS partitions so click on View and select show all devices. A word of caution, that SMART is not always going to alert you of impending failure. If you store a lot of personal files on the drive make sure you backup to another drive.

  5. john yessis says:


    Disk utility, on my Imac shows, “Smart … ” failing. Could not erase hard drive and reload Sierra.
    So i replaced it
    But, as an external drive, Smart shows no info on it. And i can now erase it using disk utility.

    What is going on?

    • Squid says:

      Most USB drive enclosures are unable to read or pass the SMART data back to your computer – there are a very VERY small percentage of enclosures I’ve used over the years that actually can do that.

  6. Lynn says:

    THANK YOU! Very interesting info (as always!)

    I was delighted to see “Verified” on my beloved, workhorse mid-2012 MBP!!!

  7. Chris says:

    The internal SATA HDD on my MacPro5,1 running macOS high sierra also says “not supported”, and its a 4TB WD that I just bought in April 2018. So, it’s not an old drive (today is June 1, 2018).

    This drive, however, has gone missing from the desktop three times now. Twice I fixed by opening my Mac Pro and re-seating the drive in bay two. The last time it re-appeared on its own. Very mysterious. Any suggestions?

  8. Tarek Ab says:

    mine as well showing “Not Supported” and I have Macbook Pro 2017 13″ 512SSD

  9. Peter says:

    PS: My Diskutility screen is different to your screenshot. I think I have added icons (right click and choose customise) in the past and that is where the ‘View’ icon appears and lets me use the show devices option.

  10. Peter says:

    On my Macbook Pro (2013) with an SSD, I had to go to the top left icon on the toolbar and check ‘Show all devices’ to see the disk. Otherwise, I only could see the Macintosh HD entry – which shows a mount point and a different set of parameters.

  11. Lance says:

    Carbon Copy Clone also backs up your OS and is bootable. Saved my bacon more than once. Definitely a sound investment. I DO still do Tm backups as well.

  12. Rogers says:

    Mine says “smart not supported”. It’s a 250GB Sandisk SSD. Does someone know why?

  13. arni says:

    Note that the new apple macbook pros with the 2TB drives – this shows S.M.A.R.T. as not supported. Probably not a big deal as no-one buys these anyway because they cost too much (except for me). If you can afford one of these you can afford a robust backup plan also.

    • Dave says:

      Try clicking the “View” Icon with down arrow just to the left of the “Disk Utility” app title. Select “Show all devices.” If the side bar is not visible click “Show Sidebar.” Highlight the top item in the side bar which on my MBP Late 2021 is “APPLE SSD AP2048R Media.” That should show “S.M.A.R.T. status: Verified.”

      The newest USB enclosures now pass S.M.A.R.T. data to your computer.

  14. Randall Miller says:

    This should have a disclaimer at the beginning or end of the article that many older machines and drives are NOT SMART enabled. Not all of us are lucky enough to have a newer Mac or Mac Book Pro.

  15. Daniel Wisehart says:

    While “Verified” is nice to know, you can get a lot more information using smartctl:

    brew install smartmontools

    smartctl -a disk0

    On my machine I got this back:

    Model Family: Apple SD/SM/TS…E/F/G SSDs
    Device Model: APPLE SSD SM1024G
    Serial Number: S299NYAG845113
    LU WWN Device Id: 5 002538 900000000
    Firmware Version: BXW5TA0Q
    User Capacity: 1,000,555,581,440 bytes [1.00 TB]
    Sector Sizes: 512 bytes logical, 4096 bytes physical
    Rotation Rate: Solid State Device
    Device is: In smartctl database [for details use: -P show]
    ATA Version is: ATA8-ACS T13/1699-D revision 4c
    SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
    Local Time is: Thu May 31 20:22:02 2018 CDT
    SMART support is: Available – device has SMART capability.
    SMART support is: Enabled

    SMART overall-health self-assessment test result: PASSED

    General SMART Values:
    Offline data collection status: (0x00) Offline data collection activity
    was never started.
    Auto Offline Data Collection: Disabled.
    Self-test execution status: ( 0) The previous self-test routine completed
    without error or no self-test has ever
    been run.
    Total time to complete Offline
    data collection: ( 0) seconds.
    Offline data collection
    capabilities: (0x53) SMART execute Offline immediate.
    Auto Offline data collection on/off support.
    Suspend Offline collection upon new
    No Offline surface scan supported.
    Self-test supported.
    No Conveyance Self-test supported.
    Selective Self-test supported.
    SMART capabilities: (0x0003) Saves SMART data before entering
    power-saving mode.
    Supports SMART auto save timer.
    Error logging capability: (0x01) Error logging supported.
    General Purpose Logging supported.
    Short self-test routine
    recommended polling time: ( 2) minutes.
    Extended self-test routine
    recommended polling time: ( 10) minutes.

    SMART Attributes Data Structure revision number: 1
    Vendor Specific SMART Attributes with Thresholds:
    1 Raw_Read_Error_Rate 0x001a 200 200 000 Old_age Always – 0
    5 Reallocated_Sector_Ct 0x0033 100 100 000 Pre-fail Always – 0
    9 Power_On_Hours 0x0032 095 095 000 Old_age Always – 20816
    12 Power_Cycle_Count 0x0032 099 099 000 Old_age Always – 65
    169 Unknown_Apple_Attrib 0x0013 240 240 010 Pre-fail Always – 7228782284544
    173 Wear_Leveling_Count 0x0032 194 194 100 Old_age Always – 12897615957
    174 Host_Reads_MiB 0x0022 099 099 000 Old_age Always – 44417934
    175 Host_Writes_MiB 0x0022 099 099 000 Old_age Always – 55161763
    192 Power-Off_Retract_Count 0x0012 099 099 000 Old_age Always – 20
    194 Temperature_Celsius 0x0022 066 029 000 Old_age Always – 34 (Min/Max 10/73)
    197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always – 0
    199 UDMA_CRC_Error_Count 0x001a 200 199 000 Old_age Always – 0

    SMART Error Log Version: 1
    No Errors Logged

    SMART Self-test log structure revision number 1
    No self-tests have been logged. [To run self-tests, use: smartctl -t]

    Warning! SMART Selective Self-Test Log Structure error: invalid SMART checksum.
    SMART Selective self-test log data structure revision number 1
    1 0 0 Not_testing
    2 0 0 Not_testing
    3 0 0 Not_testing
    4 0 0 Not_testing
    5 0 0 Not_testing
    255 0 65535 Read_scanning was never started
    Selective self-test flags (0x0):
    After scanning selected spans, do NOT read-scan remainder of disk.
    If Selective self-test is pending on power-up, resume after 0 minute delay.

  16. jnight310 says:

    the command line tool should have the info. to find it, you could dump this into terminal:

    diskutil info disk0|grep SMART

    it will show you SMART status of the boot drive. if it’s fusion or something more complicated, you could also check other drives with:

    diskutil info disk1|grep SMART
    diskutil info disk2|grep SMART


    i use something like this for checking a raid remotely. seems reliable.

  17. Jonathan says:

    I have a mid 2011 27″ iMac running Sierra 10.12.6. When I open the Disk Utility and look at the panel there’s no SMART entry at the bottom left. The disk seems to run fine and has since I bought it used a couple of years ago. Any suggestions?

    • Gregor McCormack says:

      My MacBook Pro (2015 13″) with Apple SSD also says SMART “not supported” but I learned you can enable it manually through the command line. But the thinking I have is, if Apple decided not to enable SMART on this computer and hard drive, maybe it’s not enabled for a reason. What is the effect of enabling SMART on a drive where it is not supported? Is it worth doing?

      My big thing is regular backups, it has saved my bacon a few times. Don’t skip that, hard drives DO fail and they fail randomly and for no apparent reason, particularly SSD they seem to work and then suddenly not. SSD failure is not like an HDD failure where you can sometimes hear the drive failing or sounding strange, the SSD silently fails and just stops showing up on boot, complete total failure and often data loss associated. This is what concerns me about how terrible kernel_task is with managing virtual memory because it writes so much data to the disk constantly that there is no way that is good for SSD life span.

    • morris hoodye says:

      Not all hard drive manufactures support the SMART feature. If you don’t have this feature, do not worry your drive will function normally. You just won’t get advanced warning if a future possible failure,

      • MrPete says:

        *ALL* Hard Drive manufacturers have supported SMART for decades.
        However, quite a few external drive interface mfg’s don’t.
        And a few internal chipsets don’t support it well.
        And many RAID chipsets don’t support it well.

        Worst case, one might have to remove the drive from the computer or external case, and test on a different computer.

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