Re: Write cache - Mailing list pgsql-hackers
From | ohp@pyrenet.fr |
---|---|
Subject | Re: Write cache |
Date | |
Msg-id | Pine.UW2.4.53.0401272303210.24738@server.pyrenet.fr Whole thread Raw |
In response to | Re: Write cache (Larry Rosenman <ler@lerctr.org>) |
Responses |
Re: Write cache
Re: Write cache |
List | pgsql-hackers |
On Tue, 27 Jan 2004, Larry Rosenman wrote: > Date: Tue, 27 Jan 2004 16:02:40 -0600 > From: Larry Rosenman <ler@lerctr.org> > To: ohp@pyrenet.fr > Cc: pgsql-hackers list <pgsql-hackers@postgresql.org> > Subject: Re: Write cache > > > > --On Tuesday, January 27, 2004 23:01:45 +0100 ohp@pyrenet.fr wrote: > > > On Tue, 27 Jan 2004, Larry Rosenman wrote: > > > >> Date: Tue, 27 Jan 2004 15:55:49 -0600 > >> From: Larry Rosenman <ler@lerctr.org> > >> To: ohp@pyrenet.fr > >> Cc: pgsql-hackers list <pgsql-hackers@postgresql.org> > >> Subject: Re: Write cache > >> > >> > >> > >> --On Tuesday, January 27, 2004 22:48:42 +0100 ohp@pyrenet.fr wrote: > >> > >> > On Tue, 27 Jan 2004, Larry Rosenman wrote: > >> > > >> >> Date: Tue, 27 Jan 2004 15:45:20 -0600 > >> >> From: Larry Rosenman <ler@lerctr.org> > >> >> To: ohp@pyrenet.fr > >> >> Cc: pgsql-hackers list <pgsql-hackers@postgresql.org> > >> >> Subject: Re: Write cache > >> >> > >> >> > >> >> > >> >> --On Tuesday, January 27, 2004 22:43:34 +0100 ohp@pyrenet.fr wrote: > >> >> > >> >> > On Tue, 27 Jan 2004, Larry Rosenman wrote: > >> >> > > >> >> >> Date: Tue, 27 Jan 2004 15:38:30 -0600 > >> >> >> From: Larry Rosenman <ler@lerctr.org> > >> >> >> To: ohp@pyrenet.fr, pgsql-hackers list > >> >> >> <pgsql-hackers@postgresql.org> Subject: Re: Write cache > >> >> >> > >> >> >> IDE or SCSI? > >> >> > SCSI > >> >> >> > >> >> >> Why do you think the WC is screwing you? > >> >> >> > >> >> > Because after a sys crash, the most used filesystems (databases) are > >> >> > screwed > >> >> what VxFS mount options are you using? > >> > Nothing special... And any option I could use would'nt change a thing: > >> > the cache is on the disk itself... I did'nt look physicaly yet but > >> > according to the docs there's no way to disable it lik I always did on > >> > IBM... > >> > > >> > I was forced to buy those disk (more expensive, not better) > >> define not special? > >> > >> ISTM that the driver should force it out to the disk, unless the disk is > >> lying to the driver, or the driver is buggy. > > That's exactly what I think: the DISK has a write cache so it's lying to > > the controler saying data is written when it's only in the disk cache. > > > > That also would explain the fantastic write performance I have compared to > > read... > SO, I consider these disks buggy or not acceptable for use. So do I... I have 6 disks... 250$ each... > > LER > > >> > >> > >> > > > >> >> > >> >> >> Which driver(s)? > >> >> >> > >> >> > Guess... ADPU320 > >> >> Hrm. > >> >> > >> >> >> LER > >> >> >> > >> >> >> > >> >> >> --On Tuesday, January 27, 2004 22:34:46 +0100 ohp@pyrenet.fr wrote: > >> >> >> > >> >> >> > Because I've lost a lot of data using postgresql (and I know for > >> >> >> > sure this should'nt happen) I've gone a bit further reading > >> >> >> > documentations on my disks and... > >> >> >> > > >> >> >> > I have FUJITSU MAP3367NC 36G 10000 rpm disks, those disk have a > >> >> >> > write cache of 8Mb, if someone could tell me hox to turn it > >> >> >> > off... Could'nt find it in the docs and this could very well > >> >> >> > explain why a busy database crashes every time > >> >> >> > > >> >> >> > Thanks for your help > >> >> >> > > >> >> >> > -- > >> >> >> > Olivier PRENANT Tel: +33-5-61-50-97-00 (Work) > >> >> >> > 6, Chemin d'Harraud Turrou +33-5-61-50-97-01 (Fax) > >> >> >> > 31190 AUTERIVE +33-6-07-63-80-64 (GSM) > >> >> >> > FRANCE Email: ohp@pyrenet.fr > >> >> >> > ---------------------------------------------------------------- > >> >> >> > --- --- --- ----- Make your life a dream, make your dream a > >> >> >> > reality. (St Exupery) > >> >> >> > >> >> >> > >> >> >> > >> >> >> > >> >> > > >> >> > -- > >> >> > Olivier PRENANT Tel: +33-5-61-50-97-00 (Work) > >> >> > 6, Chemin d'Harraud Turrou +33-5-61-50-97-01 (Fax) > >> >> > 31190 AUTERIVE +33-6-07-63-80-64 (GSM) > >> >> > FRANCE Email: ohp@pyrenet.fr > >> >> > ------------------------------------------------------------------- > >> >> > --- --- ----- Make your life a dream, make your dream a reality. (St > >> >> > Exupery) > >> >> > >> >> > >> >> > >> >> > >> > > >> > -- > >> > Olivier PRENANT Tel: +33-5-61-50-97-00 (Work) > >> > 6, Chemin d'Harraud Turrou +33-5-61-50-97-01 (Fax) > >> > 31190 AUTERIVE +33-6-07-63-80-64 (GSM) > >> > FRANCE Email: ohp@pyrenet.fr > >> > ---------------------------------------------------------------------- > >> > --- ----- Make your life a dream, make your dream a reality. (St > >> > Exupery) > >> > >> > >> > >> > > > > -- > > Olivier PRENANT Tel: +33-5-61-50-97-00 (Work) > > 6, Chemin d'Harraud Turrou +33-5-61-50-97-01 (Fax) > > 31190 AUTERIVE +33-6-07-63-80-64 (GSM) > > FRANCE Email: ohp@pyrenet.fr > > ------------------------------------------------------------------------- > > ----- Make your life a dream, make your dream a reality. (St Exupery) > > > > -- Olivier PRENANT Tel: +33-5-61-50-97-00 (Work) 6, Chemin d'Harraud Turrou +33-5-61-50-97-01 (Fax) 31190 AUTERIVE +33-6-07-63-80-64 (GSM) FRANCE Email: ohp@pyrenet.fr ------------------------------------------------------------------------------ Make your life a dream, make your dream a reality. (St Exupery)
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