Re: disaster recovery

From: Doug McNaught <doug(at)mcnaught(dot)org>
To: "Rick Gigger" <rick(at)alpinenetworking(dot)com>
Cc: "Bruce Momjian" <pgman(at)candle(dot)pha(dot)pa(dot)us>, "Alex Satrapa" <alex(at)lintelsys(dot)com(dot)au>, "Jason Tesser" <JTesser(at)nbbc(dot)edu>, "Pgsql (E-mail)" <pgsql-general(at)postgresql(dot)org>
Subject: Re: disaster recovery
Date: 2003-12-01 18:57:40
Message-ID: 87ptf8wel7.fsf@asmodeus.mcnaught.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

"Rick Gigger" <rick(at)alpinenetworking(dot)com> writes:

>> This is only a problem for ext2. Ext3, Reiser, XFS, JFS are all fine,
>> though you get better performance from them by mounting them
>> 'writeback'.
>
> What does 'writeback' do exactly?

AFAIK 'writeback' only applies to ext3. The 'data=writeback' setting
journals metadata but not data, so it's faster but may lose file
contents in case of a crash. For Postgres, which calls fsync() on the
WAL, this is not an issue since when fsync() returns the file contents
are commited to disk.

AFAIK XFS and JFS are always in 'writeback' mode; I'm not sure about
Reiser.

-Doug

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Jonathan Bartlett 2003-12-01 18:59:11 Re: PostgreSQL from a newcomers perspective
Previous Message Tom Lane 2003-12-01 18:54:47 Re: export FUNC_MAX_ARGS as a read-only GUC variable (was: [GENERAL] SELECT Question)