Re: can postgres run well on NFS mounted partitions?

How do you tell if a database is corrupted? Are there specific error
messages/symptoms to look for?

I have tried running multiple readers/writers, inserted data and verified
the byte count from doing fetches. I also ran a reboot and checked that the
db came back up after it with data. I still haven't done power failure test
since I'm remote and the systems are UPS'd.

Let me know how to detect corruption. Thank you all.

On Thu, Nov 12, 2015 at 1:50 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
wrote:

> On Thu, Nov 12, 2015 at 11:49 AM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
> wrote:
> > On Thu, Nov 12, 2015 at 11:19 AM, anj patnaik <patna73(at)gmail(dot)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.
>
> Also note that a UPS doesn't preclude the machine losing its power
> supplies etc, or the ever popular faulty power switch / reset button
> etc. Which I have experienced on production machines. UPS does not
> mean never having a power failure.
>