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Q: Verify USB/UASP mode in Mac OS X

Hi,

 

I would like to discern whether a connected USB hard-drive is using USB Attached SCSI transfer mode (UASP) or simply the old USB Mass Storage.

 

I have been googling and all I find is to check if IOUSBAttachedSCSI is enabled or IOUSBMassStorageClass... but both are at the same time.Screen Shot 2014-05-03 at 21.21.34.png

 

Thanks in advance!

 

Víctor

MacBook Pro with Retina display, OS X Mavericks (10.9.2)

Posted on May 3, 2014 12:30 PM

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Q: Verify USB/UASP mode in Mac OS X

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  • by Neneonline,Solvedanswer

    Neneonline Neneonline May 12, 2014 12:07 PM in response to Neneonline
    Level 1 (0 points)
    May 12, 2014 12:07 PM in response to Neneonline

    Hi,

     

    In case anyone has the same question here is the best method I have found to check UASP mode. It involves executing ioreg command under terminal. The output of this command is massive so it is better if you redirect the output to a file and then open and inspect it separately:

     

    ioreg > ~/Desktop/ioreg.txt

     

    If you open the file, it is an ASCII build tree of devices. You need to inspect the file and search for IOUSBAttachedSCSI string. You may find a line like this:

     

        | | | |       +-o IOUSBAttachedSCSI  <class IOUSBAttachedSCSI, id 0x100000d28, registered, matched, active, busy 0 (3800 ms), retain 9>

     

    If you go a couple of lines above that line (within the same hierarchy) you should see what USB device this refers to... in my case:

     

        | | | |   +-o Neutrino U3+@15111000  <class IOUSBDevice, id 0x100000d22, registered, matched, active, busy 0 (3918 ms), retain 10>

     

    The enclosure I wanted to test is in fact a Neutrino U3+ so now I know it is being driven via UAS Protocol.

     

    In case the enclosure/drive does not support UASP you should see IOUSBMassStorageClass string.

     

        | | | |       +-o IOUSBMassStorageClass  <class IOUSBMassStorageClass, id 0x1000006a9, registered, matched, active, busy 0 (3874 ms), retain 9>

     

    Well, hope this clarifies the situation and you can unconditionally assess whether a USB drive is UASP ready or not.

     

    Cheers,

     

    Víctor

  • by phocused,

    phocused phocused Nov 29, 2015 12:46 AM in response to Neneonline
    Level 1 (0 points)
    Nov 29, 2015 12:46 AM in response to Neneonline

    Nice find. A quick way to get that info, without reading through so many lines is this:

     

    $ ioreg |egrep 'IOUSBAttachedSCSI|IOUSBDevice|IOUSBMassStorageClass'

     

    It will only list the lines related to those USB entries, in my case:

     

    | |   |   +-o HP HD Webcam@1d170000  <class IOUSBDevice, id 0x10000026f, registered, matched, active, busy 0 (72 ms), retain 12>

    | |   |   | +-o IOUSBDeviceUserClientV2  <class IOUSBDeviceUserClientV2, id 0x100000398, !registered, !matched, active, busy 0, retain 7>

    | |   |   +-o BCM20702A0@1d132000  <class IOUSBDevice, id 0x100000273, registered, matched, active, busy 0 (746 ms), retain 14>

    | |   |   +-o Apple Keyboard@1d134200  <class IOUSBDevice, id 0x100000509, registered, matched, active, busy 0 (352 ms), retain 12>

    | |   |   +-o Firebird USB Flash Drive@1d140000  <class IOUSBDevice, id 0x100000631, registered, matched, active, busy 0 (463 ms), retain 9>

    | |   |       +-o IOUSBMassStorageClass  <class IOUSBMassStorageClass, id 0x100000637, registered, matched, active, busy 0 (240 ms), retain 9>

  • by norbertm,

    norbertm norbertm Aug 10, 2016 2:01 PM in response to Neneonline
    Level 1 (4 points)
    Aug 10, 2016 2:01 PM in response to Neneonline

    Hi,

    Just tried to fin out if my external USB drives really use UASP on El Capitan.

    Apparently on El Capitan the UASP driver has a new name "IOUSBMassStorageUASDriver" replacing the previous "IOUSBAttachedSCSI"

     

    e.g.:

    +-o IOUSBMassStorageUASDriver  <class IOUSBMassStorageUASDriver, id 0x100000604, registered, matched, active, busy 0 (8345 ms), retain 9>

     

    hope this is useful for someone

     

    nm