Thread: hp ciss on freebsd
Hi. We are using a HP DL 380 G5 with 4 sas-disks at 10K rpm. The controller is a built in ciss-controller with 256 MB battery-backed cache. It is partitioned as raid 1+0. Our queries are mainly selects. I will get four 72 GB sas-disks at 15K rpm. Reading the archives suggest raid 1+0 for optimal read/write performance, but with a solid raid-controller raid 5 will also perform very well when reading. Is the ciss-controller found in HP-servers a "better" raid-controller compared to the areca-raid-controller mentioned on this list? -- regards Claus When lenity and cruelty play for a kingdom, the gentlest gamester is the soonest winner. Shakespeare
On Nov 5, 2007, at 8:19 AM, Claus Guttesen wrote: > > Is the ciss-controller found in HP-servers a "better" raid-controller > compared to the areca-raid-controller mentioned on this list? > I've had great success with the P600 controller (upgraded to 512MB bbwc) plugged into an MSA70 with a pile of SAS disks. I'm using R6 (ADG) and getting some crazy good numbers with it. My newest box has a built-in p400, that did ok, but not as good as the p600. HP also has the P800 available as well. Your best bet is to load up some data, and do some testing. Check out the pgiosim project on pgfoundry, it sort of simulates a pg index scan, which is probably what you'll want to focus on more than seq read speed. -- Jeff Trout <jeff@jefftrout.com> http://www.dellsmartexitin.com/ http://www.stuarthamm.net/
On Mon, 5 Nov 2007, Claus Guttesen wrote: > Is the ciss-controller found in HP-servers a "better" raid-controller > compared to the areca-raid-controller mentioned on this list? If you search the archives for "cciss" you'll see a few complaints about this controller not working all that well under Linux. The smart thing to do regardless of what other people say is to test yourself and see if you're meeting expectations. I've got a sample of how a single disk performs with an Areca controller you can use as a baseline at http://www.westnet.com/~gsmith/content/postgresql/pg-disktesting.htm -- * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
On Nov 5, 2007, at 8:19 AM, Claus Guttesen wrote: > I will get four 72 GB sas-disks at 15K rpm. Reading the archives > suggest raid 1+0 for optimal read/write performance, but with a solid > raid-controller raid 5 will also perform very well when reading. If you only have 4 drives, I'd recommend not to go with RAID5. You want to max out spindles. The 256k RAM may not be enough of a cache too.