[gpfsug-discuss] snapshots causing filesystem quiesce

[Talamo Ivano Giuseppe (PSI)]

Dear all,

Since a while we are experiencing an issue when dealing with snapshots.
Basically what happens is that when deleting a fileset snapshot (and maybe also when creating new ones) the filesystem becomes inaccessible on the clients for the duration of the operation (can take a few minutes).

The clients and the storage are on two different clusters, using remote cluster mount for the access.

On the log files many lines like the following appear (on both clusters):
Snapshot whole quiesce of SG perf from xbldssio1 on this node lasted 60166 msec

By looking around I see we're not the first one. I am wondering if that's considered an unavoidable part of the snapshotting and if there's any tunable that can improve the situation. Since when this occurs all the clients are stuck and users are very quick to complain.

If it can help, the clients are running GPFS 5.1.2-1 while the storage cluster is on 5.1.1-0.

Thanks,
Ivano
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