Date: Sun, 15 Feb 2004 22:15:06 +0100 From: Gabriel Ambuehl <gaml@buz.ch> To: "Alvin Gunkel" <gunkel@oneofum.net> Cc: questions@freebsd.org Subject: Re: Questions about 3Ware 7506 controller Message-ID: <1163580802.20040215221506@buz.ch> In-Reply-To: <64233.68.100.34.209.1076872540.squirrel@mail.oneofum.net> References: <64233.68.100.34.209.1076872540.squirrel@mail.oneofum.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi Alvin Gunkel, you wrote. AG> -Raid 10 or 5? Compared to the 0+1 I have now, 10 would be a nice AG> improvement as loss of the one drive effectively took out two of my AG> drives. I'm not so sure whether this is entirely true. The RAID 10 thing always seemed to be more of a marketing scam than for real to me, there seem to be some people who claim RAID 10 is just a fancy name for 0+1, then again, there's also some cards that do 1+0 (i.e. mirror individual disks). Considering that you don't provide that much space, I think I might look into swapping the drives for 120 or larger drives (unless you really need the performance the 4 spindles provide over 2 but in that case, you probably want SCSI anyhow and having said so, forget about RAID 5 altogether). I never ever had any problems with rebuilding RAID 1 on Highpoint or Promise controllers. And two 120GB drives sure look cheaper to me than any Escalade whatsoever. AG> Raid 5 would give me an extra 60gb to use, but I don't have any AG> idea what the performance differential would be. Has anybody run bonnie AG> or some such test against a 7506 with raid 5 in FreeBSD? I have RAID5 on a 6410 and it really IS slow though that doesn't matter in my case, it's still plenty fast for rsyncing some hundred gigs over LAN. So if you're out for speed, I'd recommend going for RAID 10, if you need to squeeze out every last bit of space, go for RAID5. I understand 75XX series runs on faster FPGAs (at least that's the impression I always had: the chips on there aren't "real" silicon, maybe someday I'm gonna go scrape of the logo of one just to figure it out ;-) but overall I wouldn't bet on RAID5 being much faster and it certainly will never even come close to RAID 10 (physically impossible ;-). If you want to see benchmarks (albeit not on FreeBSD but that shouldn't matter that much), storagereview.com would be an excellent starting point. Keep in mind, however, that in migrating to 3ware, you *will* lose the data on the disk as the controllers insist on zeroing the array out. That's at the very least true for RAID5 (obviously) but I couldn't get the thing to do without destroying data on creating RAID1 arrays either. Regards, Gabriel
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1163580802.20040215221506>