Re: URGENT: Out of disk space pg_xlog - Mailing list pgsql-performance

From Tom Lane
Subject Re: URGENT: Out of disk space pg_xlog
Date
Msg-id 26666.1166813170@sss.pgh.pa.us
Whole thread Raw
In response to Re: URGENT: Out of disk space pg_xlog  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-performance
"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> before the system crash?  The scenario we've seen in the past is
>>
>> * data partition out of space, so writes fail
>> * each time Postgres attempts a checkpoint, writes fail, so the
>> checkpoint fails.  No data loss at this point, the dirty buffers
>> just stay in memory.
>> * pg_xlog bloats because we can't truncate away old segments

> So, at this point, if space is freed on the data partition somehow,
> Postgres recovers with no problems?  (i.e.,, the database is still
> running and no requests have been terminated abnormally due to the space
> problems?)

Right, no committed transactions have been lost.  Depending on what you
are doing, you might see individual transactions fail due to
out-of-space --- an INSERT/UPDATE that couldn't find free space within
its table would probably fail while trying to extend the table, and
anything requiring a large temp file would fail.

> Just to confirm what I would assume at this point -- non-committed
> transactions should roll back cleanly; it is reasonable to assume no
> corruption at this point?

Yeah, I would expect no problems.

            regards, tom lane

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