Обсуждение: hardware raid suggestions
I've been using the adaptec ZCR raid cards in our servers for a while now, mostly small systems with 3 or 6 disks, and we've been very happy with them. However, we're building a new DB machine with 14 U320 15K SCA drives, and we've run into a performance bottlenkeck with the ZCR card where it just won't scale well. Without going into too many details, we've tested RAID5, RAID10 and RAID50 on pretty much every array size from 4-14 disks (raid 50 tests used more drives), using JFS, reiserfs and EXT3. With every different configuration, performance didn't improve after array size became greater than 6 disks.. We used various benchmarks, including pgbench with scale factors of 10, 100, 1000, 5000 and clients of 10, 15, 30 and 45. We've done many other tests and monitoring tools, and we've come to the conclusion that the ZCR is the problem. We're looking into getting an Adaptec 2200S or the Megaraid 320 2x which have better processors, and hopefully better performance. We feel that the use of the AIC7930 as the CPU on the ZCR just doesn't cut it and a faster raid controller would work better. Does anyone out there have any experience with these cards with postgresql and linux? If so, would you be willing to share your experiences and possibly give a recommendation? --brian
Brian, > We're looking into getting an Adaptec 2200S or the Megaraid 320 2x > which have better processors, and hopefully better performance. We > feel that the use of the AIC7930 as the CPU on the ZCR just doesn't > cut it and a faster raid controller would work better. Does anyone out > there have any experience with these cards with postgresql and linux? > If so, would you be willing to share your experiences and possibly give > a recommendation? Yes, my experience with adaptecs has been universally bad. I just really don't think that "the SCSI-2 card company" is up to making high-end raid cards. MegaRaid is generally positively reviewed in a lot of places. Be careful to order the battery back-up at the same time as the Raid card; the batteries have the annoying habit of going off the market for months at a time. You should also consider looking into driver issues. In general, the RAID card drivers distributed for Linux simply aren't as good as those the same companies write for Windows or Unix. That may be your issue with the ZCR, as well as CPU. Oh, and don't bother with the upgrade if you're not getting battery backup. You need it. -- Josh Berkus Aglio Database Solutions San Francisco
Not sure what your hw platform is, but I always used to get fantastic performance from Compaq Smart Array battery backed cards. Note that I haven't bought any recently so HP may have "hp invent"-ed them... But whatever the brand - if you get a swag of battery backed cache you won't know yourself. It's fun to install an OS on them as well - watch the drive format and verify take 10 seconds ;) Another option to look at is outboard raid boxes that present a single drive "interface" to the server - I know people who swear by them. -- Mark Aufflick e mark@pumptheory.com w www.pumptheory.com (work) w mark.aufflick.com (personal) p +61 438 700 647 On 16/07/2004, at 4:07 AM, Brian Hirt wrote: > I've been using the adaptec ZCR raid cards in our servers for a while > now, mostly small systems with 3 or 6 disks, and we've been very happy > with them. However, we're building a new DB machine with 14 U320 15K > SCA drives, and we've run into a performance bottlenkeck with the ZCR > card where it just won't scale well. Without going into too many > details, we've tested RAID5, RAID10 and RAID50 on pretty much every > array size from 4-14 disks (raid 50 tests used more drives), using > JFS, reiserfs and EXT3. With every different configuration, > performance didn't improve after array size became greater than 6 > disks.. We used various benchmarks, including pgbench with scale > factors of 10, 100, 1000, 5000 and clients of 10, 15, 30 and 45. > We've done many other tests and monitoring tools, and we've come to > the conclusion that the ZCR is the problem. > > We're looking into getting an Adaptec 2200S or the Megaraid 320 2x > which have better processors, and hopefully better performance. We > feel that the use of the AIC7930 as the CPU on the ZCR just doesn't > cut it and a faster raid controller would work better. Does anyone out > there have any experience with these cards with postgresql and linux? > If so, would you be willing to share your experiences and possibly > give a recommendation? > > --brian > > > ---------------------------(end of > broadcast)--------------------------- > TIP 8: explain analyze is your friend > > ======================================================================= > = > Pain free spam & virus protection by: www.mailsecurity.net.au > Forward undetected SPAM to: spam@mailsecurity.net.au > ======================================================================= > = > ======================================================================== Pain free spam & virus protection by: www.mailsecurity.net.au Forward undetected SPAM to: spam@mailsecurity.net.au ========================================================================
> We're looking into getting an Adaptec 2200S or the Megaraid 320 2x > which have better processors, and hopefully better performance. We > feel that the use of the AIC7930 as the CPU on the ZCR just doesn't > cut it and a faster raid controller would work better. Does anyone out > there have any experience with these cards with postgresql and linux? > If so, would you be willing to share your experiences and possibly give > a recommendation? I have worked with at least four major name brands of scsi and ide raid controllers and so far the one I have found to be generally the most featured and fastest is the ICP Vortex controllers (http://www.icp-vortex.com/). It is also more expensive than the others but has been worth the cost IMHO. It has a command line utility to measure disk performance and I believe the source code for it is available. I have measured over 200 MB/s reads off these controllers on 3u disk array units. I'm sure I could have gotten more with additional tuning. Fred
Brian Hirt wrote: > I've been using the adaptec ZCR raid cards in our servers for a while > now, mostly small systems with 3 or 6 disks, and we've been very happy > with them. However, we're building a new DB machine with 14 U320 15K > SCA drives, and we've run into a performance bottlenkeck with the ZCR > card where it just won't scale well. Without going into too many > details, we've tested RAID5, RAID10 and RAID50 on pretty much every > array size from 4-14 disks (raid 50 tests used more drives), using JFS, > reiserfs and EXT3. With every different configuration, performance > didn't improve after array size became greater than 6 disks.. We used > various benchmarks, including pgbench with scale factors of 10, 100, > 1000, 5000 and clients of 10, 15, 30 and 45. We've done many other > tests and monitoring tools, and we've come to the conclusion that the > ZCR is the problem. > > We're looking into getting an Adaptec 2200S or the Megaraid 320 2x which > have better processors, and hopefully better performance. We feel that > the use of the AIC7930 as the CPU on the ZCR just doesn't cut it and a > faster raid controller would work better. Does anyone out there have any > experience with these cards with postgresql and linux? If so, would you > be willing to share your experiences and possibly give a recommendation? > Did you consider the option of use an external storage array ? We are using the dell emc CX600 http://www.dell.com/downloads/emea/products/pvaul/en/Dell_EMC_cx600_specs.pdf and I'm forgotting to have a disk behind... Regards Gaetano Mendola