On Fri, Jan 06, 2006 at 08:10:56AM -0600, Wooten, FH Frank (3934) @ IS wrote:
> Ok, I am having a huge problem getting a 400gb file server backed up. My
> master server is a unix and the file server is win2k3. I have a ESL9000
> attached to a san switch that the file server is attached too. Problem with
> the job is it will run for 4 to 5 hours and then fail with a code 84 (media
> write error). I have eliminated the tapes being the problem cause I have
> used new tapes and still get this error. I am wondering if its something
> with the switch or if it's the drives. It happens on multiple drives not
> just one. 
>  
> Any help would be greatly appreciated. This is driving me nutts. 

I've seen at least 3 different classification of 84 errors:

1.  Bad tape or tape drive.  You've eliminated this.
2.  A full disk staging unit.  You're not using DSSUs.
3.  Connectivity issues between media server and tape drive.  This is where
the fun happens...  Check your switch ports for errors on the ports.  I
had this happen when I had my ISLs set for 2Gbps and found out later
that the fibre wasn't capable of being driven at 2Gbps for that
distance.  I dropped my ISL speed to 1Gbps and it's working fine (still
out of spec and giving me buffer credit issues but error-free from the
backup point of view).  My fibre is actually being replaced now.

Have a good look at your SAN switch logs and the host error logs.  When
I had my issue, I was logging scsi errors on the hosts (even though the
drives are on the other end of a fibre/scsi bridge).

        .../Ed

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org