topic Re: Server stucks during backups on DLT in Operating System - Linux

Server stucks during backups on DLT

Muhammad Asif Anwar — Wed, 16 Jun 2004 01:02:17 GMT

Hi,

We have an LH6000 server that stucks during backups on DLT tapes. Although, some times it backup successfully but some times it just hangs and stucks. The only way to make it oprational again is a hard boot.
The configurations of our server are;

Hardware: LH6000 U3
Operating System: Red Hat 6.2
DLT Drive: HP Autoloader with COMPAQ DLT 8000

The output of cat /proc/scsi/scsi is;

##############################################

Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: NetRAID-4M RAID5 Rev: 0001
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: HP Model: NetRAID-4M RAID5 Rev: 0001
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 02 Lun: 00
Vendor: HP Model: NetRAID-4M RAID5 Rev: 0001
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: C7145-8000 Rev: 2600
Type: Medium Changer ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 01 Lun: 00
Vendor: QUANTUM Model: DLT8000 Rev: 023B
Type: Sequential-Access ANSI SCSI revision: 02
##############################################

We have used the current update driver disket for Linux 6.2 .

Please advise.

Many Thanks,
Asif

Re: Server stucks during backups on DLT

Huc_1 — Wed, 16 Jun 2004 03:43:12 GMT

If it works sometime and not other I would first try and find out if there is not more information to be had from /var/log/dmesg
var/log/* in one of theses logs you could have more informations.

ex:
"grep "scsi" /var/log/*"

If this does not give any result you could also perhaps set up for more loggin from within you backup script. "

This could take sometime.
also you are still at 6.2 ?

keep us informed.

J-P

Re: Server stucks during backups on DLT

Steven E. Protter — Wed, 16 Jun 2004 09:21:23 GMT

I would strongly consider an OS Upgrade. Also check scsi cabling and make sure the DLT drive isn't on the same scsi chain. Tape drives need to live by themselves to get maximum throughput.

SEP

Re: Server stucks during backups on DLT

Muhammad Asif Anwar — Fri, 18 Jun 2004 03:30:04 GMT

Thanks for your kind feedback.

Huc,
We use brbackup in SAP 46c to backup a 250 GB oracle database. Log messages in backup logs are not helpful to find out the reasons.
Also /var/log/* seems to have nothing to help out.
Results of "grep "scsi" /var/log/*" and logs in /var/log/dmesg are attached.

Yes, we are still at Red Hat 6.2.

SEP,
We are using SAP R/3 46C, and we are bound to use only SAP certified OS and kernels. Secondly, as per the OS support matrix, HP certifies only RedHat 6.2 with LH6000. So, we can not upgrade our OS on LH6000 at this stage.
I don't exactly know about the scsi chains, but scsi cards and devices attached are as follows;

1). Adaptec AIC-7880 SCSI
no device attached

2). HP NetRaid-4M 128MB
All HDD on RAID 5 containers

3). Adaptec AHA-2944UW Differential SCSI
HP Autoloader with DLT8000

Looking for your help.

Regards,
Asif

Re: Server stucks during backups on DLT

Muhammad Asif Anwar — Fri, 18 Jun 2004 03:30:41 GMT