I've used the megaraid / LSI cards in the past and they were pretty good
in terms of reliability, but the last one I used was the 328 model, from 4
years ago or so. that one had a battery backup option for the cache, and
could go to 128 Meg. We tested it with 4/16 and 128 meg ram, and it was
about the same with each, but we didn't do heavy parallel testing either.
Here's the page on the megaraid cards at lsilogic.com:
On Sun, 28 Sep 2003, Matt Clark wrote:
> As others have mentioned, you really ought to get battery-backed cache if
> you're doing any volume of writes. The ability to do safe write-back
> caching makes an *insane* difference to write performance.
> The site you link to also has that for only 15% more money:
> No experience with the card(s) I'm afraid.
> In general though, U320 will only be faster than U160 for large sequential
> reads, or when you have silly numbers of disks on a channel (i.e. more than
> 4/channel). If you have silly numbers of disks, then RAID5 will probably be
> better, if you have 4 disks total then RAID1+0 will probably be better. In
> between it depends on all sorts of other factors. Bear in mind though that
> if you *do* have silly numbers of disks then more channels and more cache
> will count for more than anything else, so spend the money on that rather
> than latest-and-greatest performance for a single channel.
> > -----Original Message-----
> > From: pgsql-performance-owner(at)postgresql(dot)org
> > [mailto:pgsql-performance-owner(at)postgresql(dot)org]On Behalf Of Richard
> > Jones
> > Sent: 27 September 2003 18:25
> > To: pgsql-performance(at)postgresql(dot)org
> > Subject: [PERFORM] advice on raid controller
> > Hi, i'm on the verge of buying a "MegaRAID SCSI 320-2" raid controller.
> > I need it to build a db server using 4x ultra320 scsi disks
> > i'm thinking raid 1+0 but will try with raid5 too and compare
> > Does anyone have any experience with this model, good or bad i'd like to
> > know.. thanks :)
> > as seen:
> > http://uk.azzurri.com/product/product.cgi?productId=188
> > Regards,
> > Richard.
> > PS: whoever mentioned starting a site with raid controller
> > reviews, excellent
> > idea - its hard to find decent info on which card to buy.
> > ---------------------------(end of broadcast)---------------------------
> > TIP 9: the planner will ignore your desire to choose an index scan if your
> > joining column's datatypes do not match
> ---------------------------(end of broadcast)---------------------------
> TIP 2: you can get off all lists at once with the unregister command
> (send "unregister YourEmailAddressHere" to majordomo(at)postgresql(dot)org)
In response to
pgsql-performance by date
|Next:||From: Oleg Lebedev||Date: 2003-09-29 14:35:51|
|Subject: Re: TPC-R benchmarks|
|Previous:||From: Palle Girgensohn||Date: 2003-09-29 13:45:02|
|Subject: Re: avoiding seqscan?|