On Mon, 13 Nov 2006, Guy Thornley wrote:
I've yet to find a drive that lies about write completion. The problem
is that the drives boot-up default is write-caching enabled (or perhaps
the system BIOS sets it that way). If you turn an IDE disks write cache
off explicity, using hdparm or similar
I've been trying to optimize a Linux system where benchmarking suggests
large performance differences between the various wal_sync_method options
(with o_sync being the big winner). I started that by using
src/tools/fsync/test_fsync to get an idea what I was dealing with (and to
spot which dri
Arjen,
As usual, your articles are excellent!
Your results show again that the 3Ware 9550SX is really poor at random I/O
with RAID5 and all of the Arecas are really good. 3Ware/AMCC have designed
the 96xx to do much better for RAID5, but I've not seen results - can you
get a card and test it?
W
>
> I could only find the 6 disk RAID5 numbers in the archives that were
run
> with
> bonnie++1.03. Have you run the RAID10 tests since? Did you settle on
6
> disk
> RAID5 or 2xRAID1 + 4XRAID10?
>
Unfortunately most of the tests were run with bonnie 1.9 since they were
before I realized that p
On Wed, 2006-11-22 at 11:02, Jeff Frost wrote:
> On Wed, 22 Nov 2006, Joshua D. Drake wrote:
>
> >> I could only find the 6 disk RAID5 numbers in the archives that were run
> >> with
> >> bonnie++1.03. Have you run the RAID10 tests since? Did you settle on 6
> >> disk
> >> RAID5 or 2xRAID1 + 4
On Wed, 22 Nov 2006 15:28:12 +0100
Markus Schaber <[EMAIL PROTECTED]> wrote:
> Hi, Steinar,
>
> Steinar H. Gunderson wrote:
> > On Wed, Nov 22, 2006 at 11:17:23AM +0100, Markus Schaber wrote:
> >> The Backend allocates gigs of memory (we've set sort_mem to 1
> >> gig), and then starts spilling ou
On Wed, 2006-11-22 at 09:02 -0800, Jeff Frost wrote:
> On Wed, 22 Nov 2006, Joshua D. Drake wrote:
>
> >> I could only find the 6 disk RAID5 numbers in the archives that were run
> >> with
> >> bonnie++1.03. Have you run the RAID10 tests since? Did you settle on 6
> >> disk
> >> RAID5 or 2xRAI
Jeff,
You can find some (Dutch) results here on our website:
http://tweakers.net/reviews/647/5
You'll find the AMCC/3ware 9550SX-12 with up to 12 disks, Areca 1280 and
1160 with up to 14 disks and a Promise and LSI sata-raid controller with
each up to 8 disks. Btw, that Dell Perc5 (sas) is afa
On Wed, 22 Nov 2006, Joshua D. Drake wrote:
I could only find the 6 disk RAID5 numbers in the archives that were run with
bonnie++1.03. Have you run the RAID10 tests since? Did you settle on 6 disk
RAID5 or 2xRAID1 + 4XRAID10?
Why not 6 drive raid 10? IIRC you need 4 to start RAID 10 but onl
On Wed, 2006-11-22 at 08:36 -0800, Jeff Frost wrote:
> On Wed, 22 Nov 2006, Bucky Jordan wrote:
>
> > Dells (at least the 1950 and 2950) come with the Perc5, which is
> > basically just the LSI MegaRAID. The units I have come with a 256MB BBU,
> > I'm not sure if it's upgradeable, but it looks lik
Hi, Frank,
Frank Wiles wrote:
>> The temporary data is not swapping, it's the Postgres on-disk sort
>> algorithm.
>
>Are you actually running a query where you have a GB of data
>you need to sort? If not I fear you may be causing the system
>to swap by setting it this high.
Yes,
On Wed, 22 Nov 2006, Bucky Jordan wrote:
Dells (at least the 1950 and 2950) come with the Perc5, which is
basically just the LSI MegaRAID. The units I have come with a 256MB BBU,
I'm not sure if it's upgradeable, but it looks like a standard DIMM in
there...
I posted some dd and bonnie++ benchm
Hi, Steinar,
Steinar H. Gunderson wrote:
> On Wed, Nov 22, 2006 at 11:17:23AM +0100, Markus Schaber wrote:
>> The Backend allocates gigs of memory (we've set sort_mem to 1 gig), and
>> then starts spilling out more Gigs of temporary data to the disk.
>
> How much RAM is in the server? Remember th
Dells (at least the 1950 and 2950) come with the Perc5, which is
basically just the LSI MegaRAID. The units I have come with a 256MB BBU,
I'm not sure if it's upgradeable, but it looks like a standard DIMM in
there...
I posted some dd and bonnie++ benchmarks of a 6-disk setup a while back
on a 29
On Wed, Nov 22, 2006 at 11:17:23AM +0100, Markus Schaber wrote:
> The Backend allocates gigs of memory (we've set sort_mem to 1 gig), and
> then starts spilling out more Gigs of temporary data to the disk.
How much RAM is in the server? Remember that sort_mem is _per sort_, so if
you have multiple
Hi,
PostgreSQL 8.1 (and, back then, 7.4) have the tendency to underestimate
the costs of sort operations, compared to index scans.
The Backend allocates gigs of memory (we've set sort_mem to 1 gig), and
then starts spilling out more Gigs of temporary data to the disk. So the
execution gets - in t
16 matches
Mail list logo
