On Thu, Nov 12, 2015 at 11:19 AM, anj patnaik <patna73@gmail.com> wrote: > The Linux VM where postgres is running over NFS is in a different location > than where I am. Both the NFS mounted storage and VM are on the same network > connected via 1GB ethernet switch. > > The physical server for the Linux VM has UPS. > > Is there any specific test I can run to do power failure? > > Can I reboot my VM to test this or that wouldn't be good enough? > > Also, why does a checkpoint need to run? I used the graphical installer to > install postgres so I assume it would start automatically when the server > starts. > > I was also thinking of blackhole testing. If I do a blackhole to the NFS > server would I be able to test this accurately? > > Folks in the other teams believe NFS should work fine for us so I need to > check it out. > > Your ideas are highly appreciated!
The point of the checkpoint is to make sure as much as possible is being written to the data directory when you "pull the plug". But without being able to pull the power plugs on the NAS or db server you can't really test for reliability in case of power loss. So you can't know that it'll survive one. Just disconnecting its network connection etc means it can still write out cached data if it isn't properly syncing it.
All of the above make we curious about using NFS for the data files, but having the WAL files on a local, perhaps SSD, device. I am not knowledgeable about WAL. Of course, I don't know why the OP wants to put the database files on an NFS.
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Schrodinger's backup: The condition of any backup is unknown until a restore is attempted.
Yoda of Borg, we are. Futile, resistance is, yes. Assimilated, you will be.