scsi reservation conflict

[farrukh_2]

Hi all

I am facing a strange problem.
I have two HP Hardware based server with qlogic firbe channel card installed on RHEL 3.

I recently connected these 2 server to a tape library.
Upon cat /proc/scsi/scsi I am getting all tapes.

-------------cat /proc/scsi/scsi------------OUTPUT -----
[root@test root]# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: Ultrium 2-SCSI Rev: K710
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: HP Model: Ultrium 2-SCSI Rev: K710
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 02 Lun: 00
Vendor: HP Model: Ultrium 2-SCSI Rev: K710
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 03 Lun: 00
Vendor: HP Model: Ultrium 3-SCSI Rev: M63S
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 04 Lun: 00
Vendor: HP Model: Ultrium 2-SCSI Rev: K710
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 05 Lun: 00
Vendor: HP Model: Ultrium 3-SCSI Rev: M63S
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 06 Lun: 00
Vendor: HP Model: Ultrium 3-SCSI Rev: M63S
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 07 Lun: 00
Vendor: HP Model: Ultrium 2-SCSI Rev: K710
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 08 Lun: 00
Vendor: HP Model: Ultrium 3-SCSI Rev: M63S
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 09 Lun: 00
Vendor: HP Model: Ultrium 3-SCSI Rev: M63S
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: OPEN-E*9 Rev: 2114

------------------------------------------------------------

But when I try to acess these tape drives I receives I/O error.

[root@test root]# mt -f /dev/st4 status
/dev/st4: Input/output error

-----------------------------------------
In /var/log/messages I am getting a SCSI Conflict Error.

[root@test root]# grep -i RESERVATION /var/log/messages
May 20 23:00:53 test kernel: scsi0 (0,1,0) : RESERVATION CONFLICT
May 20 23:00:53 test kernel: scsi0 (0,3,0) : RESERVATION CONFLICT
May 20 23:01:27 test kernel: scsi0 (0,1,0) : RESERVATION CONFLICT
May 20 23:01:27 test kernel: scsi0 (0,3,0) : RESERVATION CONFLICT
May 20 23:01:29 test kernel: scsi0 (0,1,0) : RESERVATION CONFLICT
May 20 23:01:29 test kernel: scsi0 (0,3,0) : RESERVATION CONFLICT
May 21 12:03:46 test kernel: scsi0 (0,2,0) : RESERVATION CONFLICT
May 23 11:49:39 test kernel: scsi0 (0,0,0) : RESERVATION CONFLICT
May 23 18:09:54 test kernel: scsi0 (0,2,0) : RESERVATION CONFLICT
May 23 18:10:29 test kernel: scsi0 (0,2,0) : RESERVATION CONFLICT
May 23 18:18:01 test kernel: scsi0 (0,2,0) : RESERVATION CONFLICT
May 23 19:46:12 test kernel: scsi0 (0,4,0) : RESERVATION CONFLICT
May 23 19:47:16 test kernel: scsi0 (0,4,0) : RESERVATION CONFLICT

---------------------------------------------
I am facing this problem on both servers. I tried but cannot get any solution.
Some where I read that some time machine reserver lun and does not release and you need to free lun so that a new devices can be used.
I am unable to figure out the solution.

Any suggestion, help for you guys..

Waiting for your reponse.

Thanks and regards
Farrukh

[Ivan Ferreira]

Are you using some backup software with these libraries?

Is there a possibility that the tape drives are in use by another host running a backup while you tried the command?

This could happen if other host is using the tape drive and issued a SCSI reservation command to prevent simultaneous access.

Depending of the library model, you can enable SCSI logging, including reservation commands.