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

Hi all

I know this didnt get a response, but I am having the same issue.

Anyone able to offer a solution or suggestions?

Thanks

Hye

do you use actual drivers provided by HP? There are smart start CD's provided by HP containing Linux drivers for the HP delivered HBA's. Also think about updating to an actual version of RHEL. Version 3 is still old.

Yeah - I use the HP drivers and I'm on RHEL 4 U8 not RHEL 3 like the original poster

thanks

Hye

it seems both hosts try to do a SCSI reservation on the devices. This will not work in case both hosts try to reserve the device for their own use.

Only one host can have access to one device on a SCSI bus. So sharing such devices requires specific mechanism provided by a special driver e.g. Veritas Netbackup tape device driver provide such functionality. Not sure, but Linux standard tape driver seems to reserve the device for himself, which only works for the first host connected to the device.

Did you test if the tape works in case only one server is connected? If yes, than this seems to be your problem.

It is apparent that if both hosts use the same shared application to access these drives then the application may have a bug in keeping track of those host Clients 'in use', before it attempts to access the tape drive(s). If there is no such application being used and the hosts are accessing the drives independently of each other, the conflict is obvious.