Re: Best OS for Postgres 8.2
От | Charles Sprickman |
---|---|
Тема | Re: Best OS for Postgres 8.2 |
Дата | |
Msg-id | Pine.OSX.4.64.0705081648060.392@hotlap.local обсуждение исходный текст |
Ответ на | Re: Best OS for Postgres 8.2 (david@lang.hm) |
Список | pgsql-performance |
On Tue, 8 May 2007, david@lang.hm wrote: > one issue with journaling filesystems, if you journal the data as well as the > metadata you end up with a very reliable setup, however it means that all > your data needs to be written twice, oncce to the journal, and once to the > final location. the write to the journal can be slightly faster then a normal > write to the final location (the journal is a sequential write to an existing > file), however the need to write twice can effectivly cut your disk I/O > bandwidth in half when doing heavy writes. worse, when you end up writing mor > ethen will fit in the journal (128M is the max for ext3) the entire system > then needs to stall while the journal gets cleared to make space for the > additional writes. > > if you don't journal your data then you avoid the problems above, but in a > crash you may find that you lost data, even though the filesystem is 'intact' > according to fsck. That sounds like an ad for FreeBSD and UFS2+Softupdates. :) Metadata is as safe as it is in a journaling filesystem, but none of the overhead of journaling. Charles > David Lang > >> Steve Atkins wrote: >>> >>> On May 7, 2007, at 2:55 PM, David Levy wrote: >>> >>> > Hi, >>> > > I am about to order a new server for my Postgres cluster. I will >>> > probably get a Dual Xeon Quad Core instead of my current Dual Xeon. >>> > Which OS would you recommend to optimize Postgres behaviour (i/o >>> > access, multithreading, etc) ? >>> > > I am hesitating between Fedora Core 6, CentOS and Debian. Can anyone >>> > help with this ? >>> >>> Well, all three you mention are much the same, just with a different >>> badge on the box, as far as performance is concerned. They're all >>> going to be a moderately recent Linux kernel, with your choice >>> of filesystems, so any choice between them is going to be driven >>> more by available staff and support or personal preference. >>> >>> I'd probably go CentOS 5 over Fedora just because Fedora doesn't >>> get supported for very long - more of an issue with a dedicated >>> database box with a long lifespan than your typical desktop or >>> interchangeable webserver. >>> >>> I might also look at Solaris 10, though. I've yet to play with it much, >>> but it >>> seems nice, and I suspect it might manage 8 cores better than current >>> Linux setups. >>> >>> Cheers, >>> Steve >>> >>> >>> >>> ---------------------------(end of broadcast)--------------------------- >>> TIP 5: don't forget to increase your free space map settings >>> >> >> Regards >> >> Ian >> >> ---------------------------(end of broadcast)--------------------------- >> TIP 3: Have you checked our extensive FAQ? >> >> http://www.postgresql.org/docs/faq >> > ---------------------------(end of broadcast)--------------------------- > TIP 1: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly >
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