Re: Problems with DAT tape....

[Timothy Shimmin <tes@boing.melbourne.sgi.com>]

Hi Steve,

On Tue, Aug 28, 2001 at 11:55:46AM -0600, Steve Wolfe wrote:
> 
>   A while ago, I took one of the machines here and started using XFS on
> it.  The kernel is 2.4.6, with the appropriate xfs patches.  All of the
> XFS stuff works marvelously, but now I'm having quite a bit of trouble
> trying to make backups to the DAT drive in it.
> 
>   After I upgraded the machine, whenever I try and send a tar to the tape
> (i.e., "trying tar cf /dev/nst0 BACKUP.LABEL"), I get:
> 
> ST0:  Write not multiple of tape block size
> 
>     The kernel does have SCSI tape and generic support, and the backup
> script hasn't changed.  I could start fiddling with mt trying to change
> the blocksize, but something just keeps nagging at me that it should be
> working, and there's probably something else that I'm missing.  Anyone
> have any ideas?
> 
> steve
> 
> 
As you mentioned in your follow up email - your scsi tape
driver had its blocksize set (large) such that the write size
that tar wanted to use was not a multiple of that block size.
As you'd see from "mt -f /dev/st0 status"
and by doing an strace on tar.

I would recommend just putting the scsi tape driver into 
variable block sized mode.

    # mt -f /dev/st0 setblk 0

--Tim