[Linux-cluster] scsi reservation issue with GFS

[Ryan O'Hara]

On Thu, Feb 19, 2009 at 11:07:12AM -0600, Alan A wrote:
>
> Thank you Ryan. This was totally correct - yet it will not let me remove the
> reservation. Here is the output of several commands I tried:
> 
> [root at fendev04 ~]# sg_persist -o -C -K 0xb0b40001 /dev/gfs_acct61/acct61
>   HP        OPEN-V            6002
>   Peripheral device type: disk
> persistent reserve out: scsi status: Reservation Conflict
> PR out: command failed
>
> ---------

Ok. The trick is that you have to attempt to clear the reservations
from a node that is registered with the device. In other words, being
registered with the device is a prerequisite for doing certain
operations, like clearing reservations and what-not.
 

> [root at fendev04 ~]# sg_persist -i -k /dev/gfs_acct61/acct61
>   HP        OPEN-V            6002
>   Peripheral device type: disk
>   PR generation=0x2, 2 registered reservation keys follow:
>     0xb0b40001
>     0xb0b40003

So we have 2 keys registered. We'll call 'em 0001 and 0003. Those
lower 32-bits are generated from the nodeid defined in cluster.conf,
so if explicitly set the nodeid's in the config file, this should help
determine which node is associated with each key.

> [root at fendev04 ~]# sg_persist -i -r /dev/gfs_acct61/acct61
>   HP        OPEN-V            6002
>   Peripheral device type: disk
>   PR generation=0x2, Reservation follows:
>     Key=0xb0b40001
>     scope: LU_SCOPE,  type: Write Exclusive, registrants only

The reservation holder is 0001. That looks fine.

Just out of curisousity, I see that that commands you were running
were from a machine named 'fendev04'. Would that happen to be nodeid
4? If so, I'm guessing that the node you are trying to run the
commands form is not registered with the device. Run the same command
(sg_persist -o -C ...) from a different node (ie. one that is still
registered with the device) and it should work.