Re: Best OS for Postgres 8.2 - Mailing list pgsql-performance

david@lang.hm wrote:
> On Tue, 8 May 2007, Claus Guttesen wrote:
>
>>> >  In #postgresql on freenode, somebody ever mentioned that ZFS from
>>> >  Solaris
>>> >  helps a lot to the performance of pgsql, so dose anyone have
>>> information
>>> >  about that?
>>>
>>>  the filesystem you use will affect the performance of postgres
>>>  significantly. I've heard a lot of claims for ZFS, unfortunantly
>>> many of
>>>  them from people who have prooven that they didn't know what they were
>>>  talking about by the end of their first or second e-mails.
>>>
>>>  much of the hype for ZFS is it's volume management capabilities and
>>> admin
>>>  tools. Linux has most (if not all) of the volume management
>>> capabilities,
>>>  it just seperates them from the filesystems so that any filesystem
>>> can use
>>>  them, and as a result you use one tool to setup your RAID, one to setup
>>>  snapshots, and a third to format your filesystems where ZFS does
>>> this in
>>>  one userspace tool.
>>
>> Even though those posters may have proven them selves wrong, zfs is
>> still a very handy fs and it should not be judged relative to these
>> statements.
>
> I don't disagree with you, I'm just noteing that too many of the 'ZFS is
> great' posts need to be discounted as a result (the same thing goes for
> the 'reiserfs4 is great' posts)
>
>>>  once you seperate the volume management piece out, the actual
>>> performance
>>>  question is a lot harder to answer. there are a lot of people who
>>> say that
>>>  it's far faster then the alternate filesystems on Solaris, but I
>>> haven't
>>>  seen any good comparisons between it and Linux filesystems.
>>
>> One could install pg on solaris 10 and format the data-area as ufs and
>> then as zfs and compare import- and query-times and other benchmarking
>> but comparing ufs/zfs to Linux-filesystems would also be a comparison
>> of those two os'es.
>
> however, such a comparison is very legitimate, it doesn't really matter
> which filesystem is better if the OS that it's tied to limits it so much
> that the other one wins out with an inferior filesystem
>
> currently ZFS is only available on Solaris, parts of it have been
> released under GPLv2, but it doesn't look like enough of it to be ported
> to Linux (enough was released for grub to be able to access it
> read-only, but not the full filesystem). there are also patent concerns
> that are preventing any porting to Linux.

This is not entirely correct. ZFS is only under the CDDL license and it
has been ported to FreeBSD.

http://mail.opensolaris.org/pipermail/zfs-discuss/2007-April/026922.html

--
Trygve