DLT Data Integrity?

1997-12-30 14:25:42
Subject: DLT Data Integrity?
From: Bob Booth - CSO <booth AT CHIANTI.CSO.UIUC DOT EDU>
Date: Tue, 30 Dec 1997 13:25:42 -0600
I am wondering if anyone has experience with AIX ADSM and DLT drives.  After
upgrading to ADSM ptf 15, I seem to be having many instances of 'SCSI' errors
on my DLT 2000XT drives.

The errors occur during read operations, like backup stg and reclaims.
I get the famous ANR8302E I/O error:

ANR8302E I/O error on drive DLTTAPE4 (/dev/mt3) (OP=LOCATE, CC=205, KEY=FF,
Description=SCSI adapter failure).  Refer to Appendix B in the 'Messages'
manual for recommended action.

I know that the 'LOCATE' on DLT's is a drive function, since it loads the
tape information into the drives memory.  ADSM is flagging the error as a
SCSI error, but it seems to be a problem with the tape.  The driver reports
this error and then ADSM rewinds the tape and verifys the label.

In some cases, the tapes are relatively new, and this can happen in any
of the drives.  I have replaced the SCSI card, but I still get the errors.
It seems that more and more of my data is becoming unreadable, and I am
starting to worry that I will not be able to retrieve data from these tapes.
I also worry, since these tapes don't have any 'write' errors, that data is
not being written correctly to the tapes, or that information is getting

Another irritation is the amount of time it is taking for these operations
to complete, since the tape is constantly being re-wound to the beginning,
which I assume is the drive reloading the TOC from the tape??

Is there any experience out there with these problems?  Is there some
advanced tracing I can use to find out if the tapes, drives, or adapters
are bad?  The error report on the AIX box, is not reporting SCSI errors, but
which yield some sense bytes.

Thanks in advance for any help, or insight!

Bob Booth
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