Giovanni Tirloni <gtirl...@sysdroid.com> writes: > I've read about these Backblaze boxes before but my feeling was that they > were built for archive/backup purposes. I just visited the site again and it > says "cheap cloud storage". I get mixed feelings about it because the our > storage servers used by the VMware/Xen hosts usually run out of IOPS before > capacity is fully utilized. > > Price, performance, capacity... pick two.
Only if you choose wisely. It's pretty easy to get only one. Like you, I run out of iops /far/ before I run out of disk bandwidth (and /far/ before a sata expander fan out system like backblaze would run out of disk bandwidth, for that matter) so while I agree that 2tb disks are kinda useless for the virtualization backend use case, Iops are usually limited by spindles, and the backblaze is a nice, cheap way to get a lot of spindles in a chassis. So yeah, for me, I'd be filling it with 500gb (or smaller) disks; I'm not seriously constrained by space. And, as almost all my accesses are random, I'm not going to be constrained by disk bandwidth on the sata expanders, either. SATA disk is just plain wimpy when it comes to random access. Of course, for backups, that's another matter. It's possible, I imagine, to set up your backups so it's mostly a sequential write; in that case, SATA does pretty good, and you might need to start worrying about the bandwidth on the sata expanders (or at the very least use the latest and fastest SATA standard, something you don't need to worry about on a one bus one disk system) and you do care about space, so the 2tb disks start looking good again. I'm just saying; if you are limited by iops on spinning disk, you are limited by spindles, and the backblaze box is one of the cheapest ways I've seen to get a bunch of those. now, reliability? I dono. For my money, I'm still getting those SuperMicro chassis with 16 disk slots. I haven't tried the backblaze. If I was to do it, I'd spend the money on a motherboard with ECC (and probably more) ram, for starters. non-ecc ram in this use case would be a total non-starter for me, and I'm very much pro-cache (of course, write cache would be... tricky... in that situation. maybe if you exported both as a iscsi lun and mirrored them on the server that used it? dangerous stuff. but the ecc isn't negotiable) -- Luke S. Crawford http://prgmr.com/xen/ - Hosting for the technically adept http://nostarch.com/xen.htm - We don't assume you are stupid. _______________________________________________ Tech mailing list Tech@lists.lopsa.org https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
