Re: streaming replication, "frozen snapshot backup on it" and missing relfile (postgres 9.2.3 on xfs + LVM)

On 14.05.2013 14:57, Benedikt Grundmann wrote:
> Today we have seen this on our testing database instance:
>
> ERROR:  could not open file "base/16416/291498116.3" (target block 431006):
> No such file or directory
>
> That database get's created by rsyncing the LVM snapshot of the standby,
> which is a readonly backup of proddb
> using streaming replication.
>
> We do not put the standby database into backup mode before rsyncing the LVM
> snapshot, trusting postgres ability to recover
> from crash.  Now we are not sure anymore...  Thoughts?  It's worth noting
> that we have been using this method of taking a backup
> for a long long time, but we only recently (after 9.2 came out we switched
> to doing a streaming replica and then to take the
> "frozen snapshot" backup method from the streaming replica).
>
> Let me know if there is more information you need, or if this is a known
> problem.

That certainly should work. I'd suggest that you narrow down the problem 
a bit more. Is the file present in the original system? Anything else 
that might be related in the logs?

- Heikki