tape drive error

[Bill Sconce]

On 13 Feb 2004 15:14:07 -0500
Charles Farinella <cfarinella at appropriatesolutions.com> wrote:

> I've started getting the following error when trying to back up to tape:
> 
> "Write not multiple of tape block size"
> 
> I need help interpreting what this means and what I might do about it.
> I've run a bunch of diagnostic tests on the drive, and have gotten mixed
> (inconsistent) results, so I kind of think it's hardware failure, but I
> still would like to know what the message is telling me.
> 
> This has worked for a year and a half, and I haven't changed anything
> that I am aware of.  HP C1536a DDS tape drive.


I had similar problems in a former life.  Unfortunately, tape handling
is one of the bang-your-head-against-the-wall areas remaining in Linux.
(Frustration-for-frustration compatibility with real Unix.  :)

I remember that the mt command was a necessary tool, FWIW.  It will let
you examine the drive's current setting (if it's a SCSI drive, anyway),
and it has a blocksize-setting option.  Your backup software is probably
closer to the problem than these background settings, so this may or
may not be of much help.

OTOH, using low-level tools like mt and dd (not trying to do a backup,
but just to push some data back and forth) might shed some light on the
problem.

-Bill

("Write not multiple of tape block size".  Right.  No mention of how big
the write request is, nor the tape block size.  No help at all.  Very much
like Unix tape handling.   Grrr.)