On Jan 18, 2008, at 4:43 PM, Brian Wipf wrote:
> On 18-Jan-08, at 2:32 PM, Erik Jones wrote:
>
>> What worries me is, that since I have a verified case of rsync
>> thinking it had successfully transferred a WAL, the same may have
>> happened with these files during the base backup. Does that
>> warning, in fact, entail that there were catalog entries for those
>> files, but that the file was not there, and by "fixing" it the
>> server just created empty files?
>
> We archive WALs directly to an NFS mount. We once had a zero-byte
> WAL file archived, which I believe was the result of a temporary
> issue with the NFS mount. We had to perform a new base backup since
> the WAL was deleted/reused by PG because it was told it was
> archived successfully. It sounds similar to the problem you
> experienced. Do you rsync to an NFS mount?
>
> If this issue is occurring when archiving WALs, I agree that it
> could be occurring when trying to get a base backup.
For our primary, er, main, onsite standby server that's also what we
do. But, this was a co-location to co-location transfer so there was
no NFS mount, it was a direct rsync to the server at the other co-
location. For WAL files, I've already decided to write a WALShipper
utility that will handle shipping WALs to multiple standbys with
verfication, but for the base backup, this is distressing. We do
have the option to do the base backup to a portable USB drive and
then carry it to the second co-lo for now. But, pretty soon we're
going to be surpassing the available limits in portably drive
capacity unless we invest in tape drives.
Erik Jones
DBA | Emma®
erik@myemma.com
800.595.4401 or 615.292.5888
615.292.0777 (fax)
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