IOSCSITape on 10.8.3

[Richard Coley]

So I had a need to read an old tape from a SCSI DAT, and had a Microtech USBSCSI converter so gave it a go..  

It didn't seem to work first off - no /dev/rst0 and I decided to download source - recompile.

Voila - /dev/rst0 appears.  I managed to read one tape with no issues, however I struggled on a couple of others.  The tapes read, all looks fine, however the contents are garbled. 

Any thoughts??

eb 15 00:41:32 Rich-Coleys-MacBook-Pro kernel[0]: rst0: <HP, C1537A, L907> tape

Feb 15 00:41:32 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 37, 0-byte blocks, write-enabled, buffered

Feb 15 00:41:32 Rich-Coleys-MacBook-Pro kernel[0]: rst0: min/max block size: 1/16777215

Feb 15 00:43:37 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 37, 131072-byte blocks, write-enabled, buffered

Feb 15 00:45:03 Rich-Coleys-MacBook-Pro kernel[0]: rst0: must be multiple of block size

Feb 15 00:45:09 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Unit Attention (Key: 0x6, ASC: 0x28, ASCQ: 0x00)

Feb 15 00:45:36 Rich-Coleys-MacBook-Pro kernel[0]: rst0: must be multiple of block size

Feb 15 00:45:46 Rich-Coleys-MacBook-Pro kernel[0]: rst0: must be multiple of block size

Feb 15 00:45:58 Rich-Coleys-MacBook-Pro kernel[0]: rst0: must be multiple of block size

Feb 15 00:46:33 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: No Sense (Key: 0x0, ASC: 0x00, ASCQ: 0x00)

Feb 15 00:46:33 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Incorrect Length Indicator (ILI)

Feb 15 00:47:04 Rich-Coleys-MacBook-Pro kernel[0]: rst0: must be multiple of block size

Feb 15 00:47:56 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 32768-byte blocks, write-protected, buffered

Feb 15 16:18:02 Rich-Coleys-MacBook-Pro kernel[0]: rst0: <HP, C1537A, L907> tape

Feb 15 16:18:02 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 37, 0-byte blocks, write-enabled, buffered

Feb 15 16:18:02 Rich-Coleys-MacBook-Pro kernel[0]: rst0: min/max block size: 1/16777215

Feb 15 16:19:37 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 32768-byte blocks, write-protected, buffered

Feb 15 16:30:30 Rich-Coleys-MacBook-Pro kernel[0]: rst0: FILEMARK DETECTED

Feb 15 16:35:29 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Unit Attention (Key: 0x6, ASC: 0x28, ASCQ: 0x00)

Feb 15 16:36:35 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: No Sense (Key: 0x0, ASC: 0x00, ASCQ: 0x00)

Feb 15 16:36:35 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Incorrect Length Indicator (ILI)

Feb 15 16:37:20 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 65536-byte blocks, write-protected, buffered

Feb 15 17:00:25 Rich-Coleys-MacBook-Pro kernel[0]: rst0: FILEMARK DETECTED

Feb 15 17:38:37 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 16384-byte blocks, write-protected, buffered

Feb 15 17:39:02 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: No Sense (Key: 0x0, ASC: 0x00, ASCQ: 0x00)

Feb 15 17:39:02 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Incorrect Length Indicator (ILI)

Feb 15 17:40:14 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 131072-byte blocks, write-protected, buffered

Feb 15 17:40:34 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: No Sense (Key: 0x0, ASC: 0x00, ASCQ: 0x00)

Feb 15 17:40:34 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Incorrect Length Indicator (ILI)

Feb 15 17:41:03 Rich-Coleys-MacBook-Pro kernel[0]: rst0: must be multiple of block size

Feb 15 17:41:46 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 65536-byte blocks, write-protected, buffered

Feb 15 17:59:54 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Unit Attention (Key: 0x6, ASC: 0x28, ASCQ: 0x00)

Feb 15 18:00:42 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: No Sense (Key: 0x0, ASC: 0x00, ASCQ: 0x00)

Feb 15 18:00:42 Rich-Coleys-MacBook-Pro kernel[0]: rst0: SENSE: Incorrect Length Indicator (ILI)

Feb 15 18:01:07 Rich-Coleys-MacBook-Pro kernel[0]: rst0: density code: 19, 32768-byte blocks, write-protected, buffered

Feb 15 18:17:04 Rich-Coleys-MacBook-Pro kernel[0]: rst0: FILEMARK DETECTED

[Jesse Peterson]

Interesting. I'll have to give a go on 10.8 at some point. Glad you got it working with a recompile, though.

Do you know what "mode" the tapes were written in? Variable blocking mode or static sized block mode? If the former then I'm afraid I may not be of much help. Clearly there's some SCSI sense codes -- possible errors going on there.

If however the latter and a static blocking size was used I'd highly suggest trying that blocking mode using the "mt" command. The "0-byte blocks" means the tape drive, and driver, are in variable mode and is the least tested mode of IOSCSITape (as I don't have any tape drives that do VBM).

Odd though - I'd expect the first block read at least to have correct data no matter what. What tools are you using to read data?

Thanks,
- Jesse

[Old Time SCSI]

I ended up compiling for 10.8.3 as well.  I modified the project to remove the debug stuff and I upped the min SDK to 10.7.  I'm seeing an issue where tar seems to fail the first time with a write error but seems to run fine after that.  I'm using an HP DAT72 via USB.  Have you seen anything similar?