> Within the thread there are instructions for using iometer to load test your > storage. You should test out your solution before going live, and compare > what you get with what you need. Just because striping 3 mirrors *will* give > you more performance than raidz2 doesn't always mean that is the best > solution. Choose the best solution for your use case.
multiple vm disks that have any kind of load on them will bury a raidz or raidz2. out of a 6x raidz2 you are going to get the iops and random seek latency of a single drive (realistically the random seek will probably be slightly worse, actually). how could that be adequate for a virtual machine backend? if you set up a raidz2 with 6x15k drives, for the majority of use cases, you are pretty much throwing your money away. you are going to roll your own san, buy a bunch of 15k drives, use 2-3u of rackspace and four (or more) switchports, and what you're getting out of it is essentially a 500gb 15k drive with a high mttdl and a really huge theoretical transfer speed for sequential operations (which you won't be able to saturate anyway because you're delivering over gige)? for this particular setup i can't really think of a situation where that would make sense. > Regarding ZIL usage, from what I have read you will only see benefits if you > are using NFS backed storage, but that it can be significant. link? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
