Reservation Conflict error meaning?

[Reshma Malusare]

Hello everyone,

We are getting this error in syslog daily..
Can somebody tell wht this error indicates?
how to stop this error?


Jun 27 20:11:01 aosrbk1 vmd[1534]: media ID 6107L1 has reached or exceeded maxmounts
Jun 27 20:11:01 aosrbk1 vmd[1534]: media ID 6163L1 has reached or exceeded maxmounts
Jun 27 20:12:23 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI3 (device 3)
Jun 27 20:12:46 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI3 (device 3)
Jun 28 00:27:52 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI3 (device 3)
Jun 28 00:28:15 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI3 (device 3)
Jun 28 00:37:47 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI1 (device 1)
Jun 28 00:38:10 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI1 (device 1)
Jun 28 01:16:33 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up
Jun 28 01:16:33 aosrbk1 vmd[1534]: media ID 6107L1 has reached or exceeded maxmounts
Jun 28 01:16:33 aosrbk1 vmd[1534]: media ID 6163L1 has reached or exceeded maxmounts
Jun 28 01:16:58 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI1 (device 1)
Jun 28 01:17:20 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI1 (device 1)
Jun 28 02:25:23 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up
Jun 28 03:02:41 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI0 (device 0)
Jun 28 03:03:05 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI0 (device 0)
Jun 28 03:07:55 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up
Jun 28 04:09:03 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up
Jun 28 04:37:55 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up
Jun 28 04:40:30 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI3 (device 3)
Jun 28 04:40:54 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI3 (device 3)
Jun 28 05:08:01 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up
Jun 28 05:32:43 aosrbk1 avrd[1576]: Reservation Conflict status from HPUltrium1-SCSI1 (device 1)
Jun 28 05:33:07 aosrbk1 avrd[1576]: Reservation Conflict status cleared from HPUltrium1-SCSI1 (device 1)
Jun 28 06:37:59 aosrbk1 ltid[1528]: Automatic cleaning of TLD(2) drive index 0 failed because there is no cleaning tape or the cleaning tape is used up

[Radovan Rovny · Accepted solution]

Hello
You are using shared SAN drives with SCSI Reserve/Release stape functionality turned on.
Reservation is sent to a tape drive by stape driver when the device is accessed to prevent multiple access to the same device. In your case, both Netbackup and stape driver are performing the same action, and this duplicate action is generating conflict status alerts.
With Netbackup/Omniback it's safe to disable this feature.
Change kernel parameter st_ats_enabled to 0

# kmtune -l -q st_ats_enabled
Parameter: st_ats_enabled
Value: 0
Default: 0
Minimum: -
Module: -

[Reshma Malusare]

I did some study & got following points..

Plese tell me i am right track -->

1]The device was unable to process the request at this time. The request should be retried by the system. No further action is
necessary. However, if the condition persists, there may be hardware problems with the device or the connectivity to the device.

2]Alternately, the device may be in the process of recovering from a powerfail cycle.

3]Alternately, there may be a problem in the configuration of the application software which is using the device causing access conflicts or bottlenecks.

4]Reservation Conflict is known to be normal message from a SCSI device that can be accessed from multiple systems.

RESERVATION CONFLICT: This status shall be returned whenever an initiator attempts to access a logical unit or an extent within a logical unit that is reserved with a conflicting reservation type for another SCSI device. The recommended initiator recovery action is to issue the command again at a later time.

5] iscsiutil -sG
If there is a non-zero value for this statistic, determine the cause of failure by either looking at the message logged in the /var/adm/syslog/syslog.log file or by monitoring the EMS/STM log file. Some of the causes for failure are:
The target device terminated the SCSI Inquiry command with a Check Condition, Busy, or Reservation Conflict status

6] 6]Severity: Serious

Description: SCSI Inquiry Command from the initiator to the target failed with cdb_status 0x!, io_status 0x!, and return value of 0x!.

Probable Cause:
*If io_status is 0x3, the session was in offline state and thus the SCSI Inquiry command could not be issued.
*If io_status is 0x4 and the return value is 0x1, the session was in transient state and thus the SCSI Inquiry command could not be issued.
*If io_status is 0x6, the connection was offline and thus the SCSI Inquiry command could not be processed.
*If io_status is 0x7, the SCSI Inquiry command failed as the number of bytes received by the initiator was less than the number of bytes the target sent.
*If cdb_status is 0x02, the target device terminated the SCSI Inquiry command with a Check Condition status.
*If cdb_status is 0x08, the target device terminated the SCSI Inquiry command with a Busy status.
*If io_status is 0x4 and the return value is 0x0, the target device did not respond to a SCSI Inquiry command within a stipulated amount of time.
*If io_status is 0x5, the SCSI Inquiry command failed due to a Target Failure - target failed to execute the command.

*If cdb_status is 0x18, the target device terminated the SCSI Inquiry command with a Reservation Conflict status.
.

Recommended Action:

*For causes 1-4, the recommended action is as follows:
Re-issue the "ioscan" command. The problem will be resolved provided it is a transient condition. If the problem persists, please contact the HP representative with the cause information.

*For causes 5-8, the recommended action is as follows:
Re-issue the "ioscan" command. The problem will be resolved provided it is a transient condition. If the problem persists, please contact the Target Vendor representative with the cause information.

*For cause #9, the recommended action is as follows:
Check the existing reservations for the target device, resolve the reservation conflict and re-issue the ioscan command.

*For cause #10, the recommended action is as follows:
Re-issue the "ioscan" command. The problem will be resolved provided the lack of memory is a transient condition. If the problem persists, please increase the physical memory size on the host system.

[Andrew Young_2]

Hi Reshma

Do you have any Windows Server 2003 servers trying to access these drives?

Regards

Andrew Y

[Reshma Malusare]

Hi,

We can access this drives..but we dont have superuser rights on this backup server.

We are connecting to this server through stepping stone.

..please tell whether above analysis is right... whts the exact error & its solution

[Andrew Young_2]

Hi Reshma

As Radovan explained something is attempting an exclusive lock on the tape devices when they are already logically locked. He believes that both the OS and the backup software are attempting to do this at the same time.

The other possibility is that since this is on a shared SAN infrastructure the tape device may be visible to other servers which may also be locking the tape devices. Microsoft Server 2003 for example has this annoying service called Removable Storage Manager or something similar which is enabled by default and grabs any tape drive it finds and can play havoc with SAN enabled tape drives.

To translate the description of the "Resolution Conflict" error message and solution that you quoted into simple English: "The tape drive that you are trying to connect to is currently busy. Please try again later." Not very helpful.

Regards

Andrew Y

[Reshma Malusare]

Hi Andrew,

I appreciate your quick response....

Can you now tell me how to stop this messages.. rather solution for this warnings.

[Andrew Young_2]

Hi Reshma

Unfortunately my experience with Netbackup is in a Windows context. Veritas has a support page with more information which might be helpful though.

http://seer.support.veritas.com/docs/252419.htm

Regards

Andrew Y

[Reshma Malusare]

Hello experts,

As suggested by andrew. i checked parameter & its 0
aosrbk1:/home/rmalusar#/usr/sbin/kmtune -l -q st_ats_enabled
Parameter: st_ats_enabled
Current: 0
Planned: 0
Default: 0
Minimum: -
Module: -
Version: -
Dynamic: No


also can some body tell me what exactly this recommended action means? what are the commands i can use?

Check the existing reservations for the target device,resolve the reservation conflict.