Would like to use IOSCSITape with USB to SCSI adapter

[Leigh House]

Hello,

I seem to be doing something a bit different in trying to connect a SCSI tape drive to a mac.

I hoped to use IOSCSITape to read data from an Exabyte 8500 tape drive through a USB-SCSI adapter.

So far, this does not work. There are no tape-related device entries in /dev, and 'mt' has not been able to  communicate with the tape drive.

Backing up a bit to describe what I've done, first I installed the IOSCSITape package, and verified the files listed in "Getting Started" went into the places described.

Then I tried communicating with the tape drive after plugging the USB-SCSI into both the tape drive and the mac. When that didn't work, I restarted the mac, with the USB-SCSI still plugged in. This does not work either.

The only entries I could find in the syslog file that seem pertinent are:

Mar 19 17:35:07 abc kernel[0]: Resetting IOCatalogue.
Mar 19 17:35:07 abc kextd[15]: 0 cached, 458 uncached personalities to catalog
Mar 19 17:35:08 abc kernel[0]: GFX0: family specific matching fails
Mar 19 17:35:08 abc kernel[0]: Matching service count = 2
Mar 19 17:35:08 abc kernel[0]: IOSCSIPeripheralDeviceNub: family specific matching fails
Mar 19 17:35:08 abc kernel[0]: Matching service count = 5
Mar 19 17:35:09 abc kernel[0]: GFX0: family specific matching fails

Additional information:

1. The hardware:

USB-SCSI adapter: Ratoc U2SCXU. It is powered by the SCSI bus in the tape drive enclosure. I bought this new.

Exabyte: Model 8500 in Sun Microsystems enclosure. This is a used tape drive, though I expect it probably is fully working. Nevertheless I have not yet actually tested it.

Computer: Mac Book Pro (2 yrs old), OSX 10.5.8 (this is a laptop, thus I need a USB-SCSI adapter).

2. With the USB-SCSI adapter plugged in to both the computer and the tape drive, System Profiler reports:

USB High-Speed Bus:

 Host Controller Location: Built In USB
 Host Controller Driver: AppleUSBEHCI
 PCI Device ID:   0x2836
 PCI Revision ID: 0x0004
 PCI Vendor ID: 0x8086
 Bus Number: 0xfd

   USB-SCSI Converter:
     Product ID: 0x0222
     Vendor ID: 0x0584 (RATOC System Inc.)
     Version: 1.11
     Serial Number: 020301002dce
     Speed: Up to 480 Mb/sec
     Manufacturer: RATOCSystems,Inc.
     Location ID: 0xfd100000
     Current Available (mA): 500
     Current Required (mA): 2

3. I found an old Adaptec USBconnect (or is it called USBXchange?), which was orphaned by Adaptec, at least as far as using it with a Mac. With that plugged into the tape drive and the computer, System Profiler simply notes it sees an "unidentified" USB device. So at least the Ratoc is getting recognized by the mac.

Since I am trying to use a USB to SCSI adapter, is this type of SCSI connection likely to work at all with IOSCSITape?

If no, I guess I'll look around for a Sun workstation (or something comparable, though that is kind of a pain) to read my tapes.

If yes, any suggestions on what I should try next?

Thanks very much,
Leigh

[Jesse Peterson]

Hello Leigh,

My replies are inline...

On Mon, Mar 21, 2011 at 9:23 PM, Leigh House <haga...@gmail.com> wrote:

Hello,

I seem to be doing something a bit different in trying to connect a SCSI tape drive to a mac.

I hoped to use IOSCSITape to read data from an Exabyte 8500 tape drive through a USB-SCSI adapter.

This should work and it seems like you've done all the correct steps. As you of course noticed IOSCSITape has not detected the drive, however.

1. The hardware:

USB-SCSI adapter: Ratoc U2SCXU. It is powered by the SCSI bus in the tape drive enclosure. I bought this new.

Exabyte: Model 8500 in Sun Microsystems enclosure. This is a used tape drive, though I expect it probably is fully working. Nevertheless I have not yet actually tested it.

Computer: Mac Book Pro (2 yrs old), OSX 10.5.8 (this is a laptop, thus I need a USB-SCSI adapter).

While I don't have experience with the named Ratoc unit, I have seen SCSI-Firewire adapters work fine. I haven't seen the 8500 tape drive, either, but asume it should also work okay.
 

2. With the USB-SCSI adapter plugged in to both the computer and the tape drive, System Profiler reports:

USB High-Speed Bus:

 Host Controller Location: Built In USB
 Host Controller Driver: AppleUSBEHCI
 PCI Device ID:   0x2836
 PCI Revision ID: 0x0004
 PCI Vendor ID: 0x8086
 Bus Number: 0xfd

   USB-SCSI Converter:
     Product ID: 0x0222
     Vendor ID: 0x0584 (RATOC System Inc.)
     Version: 1.11
     Serial Number: 020301002dce
     Speed: Up to 480 Mb/sec
     Manufacturer: RATOCSystems,Inc.
     Location ID: 0xfd100000
     Current Available (mA): 500
     Current Required (mA): 2

This is likey the problem here. Below (or above or near) this SCSI converter should be the listing for Exabyte drive itself. Unfortunately if the underlying SCSI bus is not seeing the tape drive then IOSCSITape (nor anything I suspect) will be able to use the drive. IOSCSITape uses any "SCSI-bus" sequential device detected by the OS--but it must be detected by the OS first.

To further debug this I would drop to the Terminal and issue this command:

% ioreg -r -c IOSCSIPeripheralDeviceNub

One of the listings should be the tape drive. For example here is a USB-connected Sony AIT-1 drive (in a LaCie enclosure):

jesse@Jesses-MBP:~% ioreg -r -c IOSCSIPeripheralDeviceNub  
+-o IOSCSIPeripheralDeviceNub  <class IOSCSIPeripheralDeviceNub, id 0x1000009b7, registered, matched, active, busy 0 (6 ms), retain 5>
  | {
  |   "IOClass" = "IOSCSIPeripheralDeviceNub"
  |   "CFBundleIdentifier" = "com.apple.iokit.IOSCSIArchitectureModelFamily"
  |   "IOProviderClass" = "IOSCSIProtocolServices"
  |   "IOCFPlugInTypes" = {"7D66678E-08A2-11D5-A1B8-0030657D052A"="IOSCSIArchitectureModelFamily.kext/Contents/PlugIns/SCSITaskUserClient.kext/Conten$
  |   "SCSITaskDeviceCategory" = "SCSITaskUserClientDevice"
  |   "IOUserClientClass" = "SCSITaskUserClient"
  |   "IOProbeScore" = 0
  |   "Peripheral Device Type" = 1
  |   "IOMatchCategory" = "SCSITaskUserClientIniter"
  |   "Vendor Identification" = "SONY"
  |   "Protocol Characteristics" = {"Physical Interconnect"="USB","Read Time Out Duration"=30000,"Physical Interconnect Location"="External","Write T$
  |   "Product Revision Level" = "0103"
  |   "SCSITaskUserClient GUID" = <00ee5a132700bf11ec080000>
  |   "Product Identification" = "SDX-420C"
  | }

Of very specific note here is the "Peripheral Device Type" = 1. THis indicates a sequential (tape) device. SDX-420C is the Sony model number for an ATAPI AIT-1 drive, with a firmware rev. of 0103.

You should see a similar entry for your Exabyte, assuming the SCSI bridge is working. I assume all the cabling is good with a parallel SCSI terminator and all that?

All of this can be done without having IOSCSITape installed, too. Just for reference my system profiler looks like this for this drive:

    USB High-Speed Bus:

      Host Controller Location: Built-in USB
      Host Controller Driver: AppleUSBEHCI
      PCI Device ID: 0x0aa6
      PCI Revision ID: 0x00b1
      PCI Vendor ID: 0x10de
      Bus Number: 0x24

        LaCie StudioDrive USB2        :

          Product ID: 0x0204
          Vendor ID: 0x059f  (LaCie)
          Version: 11.06
          Serial Number: 11100E00060B3834

          Speed: Up to 480 Mb/sec

          Manufacturer: LaCie
          Location ID: 0x24100000
          Current Available (mA): 500
          Current Required (mA): 98

And again for reference when IOSCSITape sees the drive it'll look similar to this:

Mar 23 23:23:15 Jesses-MBP kernel[0]: rst0: <SONY, SDX-420C, 0103> tape
Mar 23 23:23:15 Jesses-MBP kernel[0]: rst0: density code: 48, 512-byte blocks, write-enabled, buffered
Mar 23 23:23:15 Jesses-MBP kernel[0]: rst0: min/max block size: 2/16777215

 

3. I found an old Adaptec USBconnect (or is it called USBXchange?), which was orphaned by Adaptec, at least as far as using it with a Mac. With that plugged into the tape drive and the computer, System Profiler simply notes it sees an "unidentified" USB device. So at least the Ratoc is getting recognized by the mac.

Yeah if the OS can't see the bus then I'd doubt it'd work.
 

Since I am trying to use a USB to SCSI adapter, is this type of SCSI connection likely to work at all with IOSCSITape?

Indeed. IOSCSITape is abstracted from all the bus connectivity and details. So as long as the bus connectivity is working correctly, and the drive is properly reported to the OS, then it should be good to go.
 

If yes, any suggestions on what I should try next?

The key here, I think, will be to get OS X to see the tape drive on the SCSI bus. If the SCSI bus can communicate with the SCSI tape drive (at a base level) then IOSCSITape and turn that into the /dev/rst0 device we know and love.
 
Thanks, hope this helps, and interested to hear back!
- Jesse

[Leigh House]

Jesse,
Thanks very much for your insights and suggestions. Your additional information will help me a lot.

It seemed like wishful thinking that IOSCSITape would work with anything but a SCSI plug in card, so I'm delighted to hear that it should work with a USB-SCSI adapter.

Although the SCSI bus termination should be right, it is worth checking again (it has been easy to forget about the intricacies of SCSI with the simplicity of USB and Firewire).

Now to see if I can't coax them to work.

Leigh