Обсуждение: Raw vs Filesystem

    Hello  Jaime,

    I think you're on the right track but have gotten some
    concepts possibly confused.

    As I remember,   the original email asked if Postgres
    could be run in a "raw" mode.   Another submitter
    told us that it can not.   ( Did I read that correctly, everyone ? )

    This means run Postgress in a raw or character mode versus
    the "standard" block mode as you would handle other files
    in a filesystem.     The primary advantage for a raw mode
    is speed.  ORACLE allows this method of operation.

    So ... your last question is now rather moot.   For best
    performance assure your setup parameters and Linux
    kernel parameters are optimized.      Help with that
    is a few keystrokes from anywhere.

                Terry



Jaime Casanova wrote:

 > Can you tell me (or at least guide me to a palce where i can find the
 > answer) what are the benefits of filesystems over raw devices?
 >
 > And what filesystem is the best for postgresql performance?
 >


--
Terry L. Hampton
Project Manager
LimaCorp, LLC   www.limacorp.com
513.587.1874

ok. if i don't misunderstand you (english is not my mother tongue, so i can
be wrong). your point is that speed is not necesarily performance, that's
right.

so, the real question is what is the best filesystem for optimal speed in
postgresql?

_________________________________________________________________
MSN 8 with e-mail virus protection service: 2 months FREE*
http://join.msn.com/?page=features/virus

el_vigia_ec@hotmail.com ("Jaime Casanova") asked:
> so, the real question is what is the best filesystem for optimal speed
> in postgresql?

The smart-alec answer would be... "Veritas, of course!"

But seriously, it depends on many factors you have not provided
information about.

-> Different operating systems support different filesystems; you
   should probably specify what OS you are using.

-> Hardware choices have ENORMOUSLY more impact on speed than any
   choice of filesystems.

If your hardware is too slow, changing filesystems will not help you.

And you would be _way_ better off with a filesystem that is 3% slower
if it improves reliability by a significant factor.
--
wm(X,Y):-write(X),write('@'),write(Y). wm('cbbrowne','acm.org').
http://www3.sympatico.ca/cbbrowne/lsf.html
"We should start referring to processes which run in the background by
their correct technical name:... paenguins."  -- Kevin M Bealer

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Am Dienstag, 30. März 2004 06:00 schrieb Christopher Browne:
> el_vigia_ec@hotmail.com ("Jaime Casanova") asked:
> > so, the real question is what is the best filesystem for optimal speed
> > in postgresql?
>
> The smart-alec answer would be... "Veritas, of course!"
>
> But seriously, it depends on many factors you have not provided
> information about.
>
> -> Different operating systems support different filesystems; you
>    should probably specify what OS you are using.
>
> -> Hardware choices have ENORMOUSLY more impact on speed than any
>    choice of filesystems.

One method for further optimizing access on database files can be to mount the
partition where the database files are kept in a fashion that omits most of
the bookkeeping of the filesystem, e.g. using the -noatime option.  Any
filesystem that is heavily accessed will greatly benefit from this -
especially if the filesystem resides on a RAID 5 disk array since updating
the access times will cause any checksums to be re-computed and written back
to the array.


hth,

  Torsten

- --
InWise - Wirtschaftlich-Wissenschaftlicher Internet Service GmbH
Waldhofstraße 14                            Tel: +49-4101-403605
D-25474 Ellerbek                            Fax: +49-4101-403606
E-Mail: info@inwise.de            Internet: http://www.inwise.de
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)

iD8DBQFAcmuunSCI/lmEFI8RAtE+AKDeKS63Yt7fkhiZ3OAH8tj2uXQ7HgCguQ4s
34VyZ5+9Vuum9nmDaDblsSs=
=6B+8
-----END PGP SIGNATURE-----