On Nov 19, 2012, at 12:01 AM, Paul B. Henson wrote: >>> the 313 has a supercapacitor to flush the write cache on unexpected >>> power failure. >> >> They don't unfortunately. > > Bummer :(, it would be nice to get one that does. I think the 320 series > does, the 40G is only $90, but I think it has relatively crappy write > performance and high write latency, so wouldn't be a very good zil. The > 313 looks like it has pretty good performance, and not too pricy at $135 > for 24G, which is plenty big for a zil. The box is going to have dual > power supplies on UPS's, and I plan to set it up for auto shutdown on > power loss, so it's not *too* likely the slog is going to unexpectedly > lose power while processing writes. I guess when you're on a budget you > can't have everything <sigh>, I might need to settle for a non-powerfail > protected ssd for zil...
You might also consider one of the larger capacities of the 320 series. They seem to offer a near linear increase in write performance as you boost the capacity. Since you only need a small portion of the SSD for Zil (say 8GB) the larger models also you get increased durability. Don't know about write latency, but Intel claims 90us. If you look at Intel's comparison, specifically the Sequential Write and Random Write (8GB Span) you get the following: Size: Random write (8GB span) / sequential write 40GB: 3.7K IOPS / 45MB/sec 80GB: 10K IOPS / 90MB/sec 120GB: 14K IOPS / 130MB/sec 160GB: 21K IOPS / 165MB/sec 300GB: 23K IOPS / 205MB/sec. Source: http://ark.intel.com/compare/56568,56571,56563,56565,56567,56569 Also, the Anandtech's review: http://www.anandtech.com/show/4244/intel-ssd-320-review The 300GB model is $450 and the160GB is half as much at $275. Also in case you want to confirm which Intel SSDs include a super capacitor the term they use on ark.intel.com is "Enhanced Power Loss Data Protection". ZFSBuild.com (they guys behind 'NoSupportLinuxHosting.com') are testing mirrored 20GB Intel 313 series SSDs for Zil. You might consider those too. -Pete ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
