Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Greg Smith
On Thu, 21 May 2009, Scott Marlowe wrote: But in a RAID-10 you aggreate pairs like RAID-0, so you could write 250(n/2) times per second on 15k where n=4 and 166(n/2) for 10k drives where n=8. So 500 versus 664... ? Or am I getting it wrong. Adding more spindles doesn't improve the fact that

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Greg Smith
On Thu, 21 May 2009, Robert Schnabel wrote: A word of warning for anyone out there considering the Seagate 1.5TB SATA drives (ST31500341AS)...I'm going through a fiasco right now with these drives and I wish I had purchased more when I did. Those drives are involved in the worst firmware deba

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Linos
Thanks for all the suggestions i will go with 8 10k disks, well 9 if you count the spare now that i am scared :) Regards, Miguel Angel. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-pe

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Robert Schnabel
Greg Smith wrote: On Thu, 21 May 2009, Robert Schnabel wrote: A word of warning for anyone out there considering the Seagate 1.5TB SATA drives (ST31500341AS)...I'm going through a fiasco right now with these drives and I wish I had purchased more when I did. I don't think you came to the right

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Greg Smith
On Fri, 22 May 2009, Robert Schnabel wrote: No, the original drives I have work fine. The problem, as you point out, is that Seagate changed the firmware and made it so that you cannot flash it to a different version. The subtle point here is that whether a drive has been out long enough to

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Scott Marlowe
On Fri, May 22, 2009 at 9:08 AM, Greg Smith wrote: > On Fri, 22 May 2009, Robert Schnabel wrote: > >> No, the original drives I have work fine.  The problem, as you point out, >> is that Seagate changed the firmware and made it so that you cannot flash it >> to a different version. > > The subtle

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Greg Smith
On Fri, 22 May 2009, Scott Marlowe wrote: It's much less common to see such a change in server class drives This is a good point, and I just updated http://wiki.postgresql.org/wiki/SCSI_vs._IDE/SATA_Disks with a section about this topic (the last one under "ATA Disks"). -- * Greg Smith gsm

Re: [PERFORM] raid10 hard disk choice

2009-05-22 Thread Robert Schnabel
Greg Smith wrote: On Fri, 22 May 2009, Scott Marlowe wrote: It's much less common to see such a change in server class drives This is a good point, and I just updated http://wiki.postgresql.org/wiki/SCSI_vs._IDE/SATA_Disks with a section about this topic (the last one under "ATA Disks"). An

Re: [PERFORM] Bad Plan for Questionnaire-Type Query

2009-05-22 Thread David Blewett
On Sat, May 9, 2009 at 11:52 AM, Tom Lane wrote: > David Blewett writes: > > On Fri, May 8, 2009 at 10:00 PM, Tom Lane wrote: > >> Thanks. Could I trouble you for one other data point --- about how many > >> rows are in each of these tables? > > > Not a problem: > > As best I can tell, the sel

Re: [PERFORM] Full statement logging problematic on larger machines?

2009-05-22 Thread Frank Joerdens
On Fri, Mar 20, 2009 at 8:47 PM, Frank Joerdens wrote: > On Thu, Mar 12, 2009 at 1:38 PM, Frank Joerdens wrote: >> On Thu, Mar 12, 2009 at 1:45 AM, Tom Lane wrote: >> [...] >>> You could try changing _IOLBF >>> to _IOFBF near the head of postmaster/syslogger.c and see if that helps. > > The patc