[gpfsug-discuss] AFM cache rolling upgrade with minimal impact / no directory scan

Billich Heinrich Rainer (ID SD) heinrich.billich at id.ethz.ch
Tue Aug 25 16:13:03 BST 2020


We will upgrade a pair of AFM cache nodes which serve about 40 SW filesets. I want to do a rolling upgrade. I wonder if I can minimize the impact of the failover when filesets move to the other afm node.  I can't stop replication during the upgrade: The update will take too long (OS, mofed, FW, scale) and we want to preserve the ability to recall files (?). Mostly I want to avoid policy scans of all inodes on cache  (and maybe even lookups of files on home??) 
I can stop replication for a short time. Also the queues most of the time are empty or contain just a few 100 entries. The cache filesets holds about 500M used inodes. Does a specific procedure exist, or is it good enough to just shutdown scale on the node I want to update? And maybe flush the queues first as  far as possible? 

If a fileset has a zero length queue of pending transactions to home, will this avoid any policy scan when a second afm node takes responsibility for the fileset?

Maybe I did already ask this before. Unfortunately the manual isn't as explicit as I would prefer when it talks about rolling upgrades.

Thank you,


Heinrich Billich
ETH Zürich
Tel.: +41 44 632 72 56
heinrich.billich at id.ethz.ch

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