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pNFS client behavior confirmation

DISCUSSION Mkrtchyan, Tigran 1 participant 2 messages Jun 11, 2014 1 message not in the archive

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#1 lore raw

Dear pnfs developers,

I would like to confirm client behavior which was hurting us for years.

If for some reason the client is unable to connect to a DS, then this DS got blacklisted and the only way to whitelist it again was client reboot. With RHEL7 (and I believe with upstream kernel), after 2 mins client 'forgets' about bad DS and uses it again. This behavior is tested and confirmed during June bakeathon.

Missing bits:

i) it takes client 6 min to fall back to MDS, e.g time between LAYOUTGET and first WRITE to MDS ii) there are no log entries why client have decided to use MDS

Thanks,
Tigran.

#2 lore raw

Dear pnfs developers,

I would like to confirm client behavior which was hurting us for years.

If for some reason the client is unable to connect to a DS, then this DS got blacklisted and the only way to whitelist it again was client reboot. With RHEL7 (and I believe with upstream kernel), after 2 mins client 'forgets' about bad DS and uses it again. This behavior is tested and confirmed during June bakeathon.

Missing bits:

i) it takes client 6 min to fall back to MDS, e.g time between LAYOUTGET and first WRITE to MDS ii) there are no log entries why client have decided to use MDS

Thanks,
Tigran.