Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-13 Thread Cott Lang
> Having WAL on a separate drive from the database would be something of > a win. I'd buy that 1 disk for OS+WAL and then RAID [something] > across the other two drives for the database would be pretty helpful. Just my .02, I did a lot of testing before I deployed our ~50GB postgresql databases

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Josh Berkus
RIchard, > its a dual xeon 2.4, 4gb ram and 3x identical 15k rpm scsi disks > > should i mirror 2 of the disks for postgres data, and use the 3rd disk for the > o/s and the pg logs or raid5 the 3 disks or even stripe 2 disks for pg and > use the 3rd for o/s,logs,backups ? I'd mirror 2. Str

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Vivek Khera
> "WL" == Will LaShell <[EMAIL PROTECTED]> writes: WL> o the performance issues. Check the linux megaraid driver list archives WL> to see the full description. I've seen it come up many times and WL> basically all the problems have turned up resolved. I've seen this advice a couple of times,

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Richard Jones
The dual xeon arrangement is because the machine will also have to do some collaborative filtering which is very cpu intensive and very disk un-intensive, after loading the data into ram. On Friday 12 September 2003 5:49 pm, you wrote: > RIchard, > > > its a dual xeon 2.4, 4gb ram and 3x identi

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Rod Taylor
On Fri, 2003-09-12 at 12:55, Richard Jones wrote: > The machine is coming from dell, and i have the option of a > PERC 3/SC RAID Controller (32MB) > or software raid. > > does anyone have any experience of this controller? > its an additional £345 for this controller, i'd be interested to know w

Re: [PERFORM] best arrangement of 3 disks for (insert) performance - Dell

2003-09-12 Thread Christopher Browne
[EMAIL PROTECTED] ("Thom Dyson") writes: > The Dell PERC controllers have a very strong reputation for terrible > performance. If you search the archives of the Dell Linux Power > Edge list (dell.com/linux), you will find many, many people who get > better performance from software RAID, rather th

Re: [PERFORM] best arrangement of 3 disks for (insert) performance - Dell

2003-09-12 Thread Vivek Khera
> "TD" == Thom Dyson <[EMAIL PROTECTED]> writes: TD> The Dell PERC controllers have a very strong reputation for terrible TD> performance. If you search the archives of the Dell Linux Power Edge list TD> (dell.com/linux), you will find many, many people who get better TD> performance from sof

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Will LaShell
I would like to point out though on the PERC controllers that are LSI based ( Megaraid ) there -are- settings that can be changed to fix any o the performance issues. Check the linux megaraid driver list archives to see the full description. I've seen it come up many times and basically all the pr

Re: [PERFORM] best arrangement of 3 disks for (insert) performance - Dell

2003-09-12 Thread Thom Dyson
The Dell PERC controllers have a very strong reputation for terrible performance. If you search the archives of the Dell Linux Power Edge list (dell.com/linux), you will find many, many people who get better performance from software RAID, rather than the hw RAID on the PERC. Having said that, th

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Richard Jones
The machine is coming from dell, and i have the option of a PERC 3/SC RAID Controller (32MB) or software raid. does anyone have any experience of this controller? its an additional £345 for this controller, i'd be interested to know what people think - my other option is to buy the raid control

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Christopher Browne
[EMAIL PROTECTED] (Richard Jones) writes: > I have some new hardware on the way and would like some advice on > how to get the most out of it.. > > its a dual xeon 2.4, 4gb ram and 3x identical 15k rpm scsi disks > > should i mirror 2 of the disks for postgres data, and use the 3rd > disk for the

Re: [PERFORM] best arrangement of 3 disks for (insert) performance

2003-09-12 Thread Matt Clark
> the machine will be dealing with lots of inserts, basically as many as we can > throw at it If you mean lots of _transactions_ with few inserts per transaction you should get a RAID controller w/ battery backed write-back cache. Nothing else will improve your write performance by nearly as muc