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

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

> "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

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] software vs hw hard on linux

My personal experience with RAID cards is that you have to spend money to get good performance. You need battery backed cache because RAID 5 only works well with write to cache turned on, and you need a good size cache too. If you don't have it, RAID 5 performance will suck big time. If you n

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

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] software vs hw hard on linux

[EMAIL PROTECTED] (Jeff) writes: > On the pro-sw side you have lots of speed and less cost (unfortunately, > there is a pathetic budget so spending $15k on a raid card is out of the > question really). I have been playing with a Perq3 QC card whic

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

[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

> "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] software vs hw hard on linux

> "J" == Jeff <[EMAIL PROTECTED]> writes: J> Due to various third party issues, and the fact PG rules, we're planning J> on migrating our deplorable informix db to PG. It is a rather large DB J> with a rather high amount of activity (mostly updates). So I'm going to If at all possible, bat

Re: [PERFORM] software vs hw hard on linux

> "a" == aturner <[EMAIL PROTECTED]> writes: a> you need a good size cache too. If you don't have it, RAID 5 a> performance will suck big time. If you need speed, RAID 10 seems a> to be the only way to go, but of course that means you are gonna a> spend $$s on drives and chasis. I wish som

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

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

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] software vs hw hard on linux

Jeff, > What I'm wondering about is what folks experience with software raid vs > hardware raid on linux is. A friend of mine ran a set of benchmarks at > work and found sw raid was running obscenely faster than the mylex and > (some other brand that isn't 3ware) raids.. Our company has stopped

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

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

[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] [GENERAL] how to get accurate values in pg_statistic

On Thu, 11 Sep 2003, Christopher Browne wrote: > [EMAIL PROTECTED] ("scott.marlowe") writes: > > On Thu, 11 Sep 2003, Tom Lane wrote: > > > >> Christopher Browne <[EMAIL PROTECTED]> writes: > >> > The "right answer" for most use seems likely to involve: > >> > a) Getting an appropriate number of

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

Hi all, 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 o/s and the pg logs or raid5 the 3 disks or

[PERFORM] software vs hw hard on linux

Due to various third party issues, and the fact PG rules, we're planning on migrating our deplorable informix db to PG. It is a rather large DB with a rather high amount of activity (mostly updates). So I'm going to be aquiring a dual (or quad if they'll give me money) box. (In my testing my glor

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

> 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