On Mon, Jul 13, 2009 at 4:08 PM, Richard Mahlerwein<mahle...@yahoo.com> wrote: >> > Just as a question: how ARE you planning on backing >> this beast up? While I don't want to sound like a >> worry-wort, I have had odd things happen at the worst of >> times. RAID cards fail, power supplies let out the magic >> smoke, users delete items they really want back... *sigh* >> >> Rsync over ssh to another server. Most of the data stored >> will never >> change after the first upload. A daily rsync run will >> transfer one or >> two gigs at the most. History is not required for the same >> reason; >> this is an append-only storage for the most part. A backup >> for the >> previous day is all that is required, but I will keep a >> weekly backup >> as well until I start running out of space. >> >> > A bit of reading shows that ZFS, if it's stable >> enough, has some really great features that would be nice on >> such a large pile o' drives. >> > >> > See http://wiki.freebsd.org/ZFSQuickStartGuide >> > >> > I guess the last question I'll ask (as any more may >> uncover my ignorance) is if you need to use hardware RAID at >> all? It seems both UFS2 and ZFS can do software RAID >> which seems to be quite reasonable with respect to >> performance and in many ways seems to be more robust since >> it is a bit more portable (no specialized hardware). >> >> I've thought about this one a lot. In my case, the hard >> drives are in >> a separate enclosure from the server and the two had to be >> connected >> via SAS cables. The 9690SA-8E card was the best choice I >> could find >> for accessing an external SAS enclosure with support for 8 >> drives. >> >> I could configure it in JBOD mode and then use software to >> create a >> RAID array. In fact, I will likely do this to compare >> performance of a >> hardware vs. software RAID5 solution. The ZFS RAID-Z option >> does not >> appeal to me, because the read performance does not benefit >> from >> additional drives, and I don't think RAID6 is available in >> software. >> For those reasons I'm leaning toward a hardware >> implementation. >> >> If I go the hardware route, I'll try to purchase a backup >> controller >> in a year or two. :) >> >> > There are others who may respond with better >> information on that front. I've been a strong >> proponent of hardware RAID, but have recently begun to >> realize many of the reasons for that are only of limited >> validity now. >> >> Agreed, and many simple RAID setups (0, 1, 10) will give >> you much >> better performance in software. In my case, I have to have >> some piece >> of hardware just to get to the drives, and I'm guessing >> that hardware >> RAID5/6 will be faster than the closest software >> equivalent. Maybe my >> tests will convince me otherwise. >> >> - Max > > I'd love to hear about any test results you may get comparing software with > hardware raid.
I received the hardware yesterday. There was a last minute change due to cost. Instead of getting 4x 2TB drives I opted for 6x 1TB. This limits my future expansion a bit, but that may be a few years down the line. On the plus side, I can get the 4TB of RAID6 that I originally planned for and the performance should be better because of additional disks in the array. Sometime next week I'll install FreeBSD 8 and will then be able to run a few benchmarks. After that I'll configure software RAID and repeat the process. Are there any specific tests that you guys would like me to run? Sequential read/write tests using dd are a given, beyond that I'm not familiar with any ports under benchmarks/, so if you know of anything good, tell me. - Max _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"