-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 milosz a écrit : >> 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. Ouch ! Pretty direct answer. That's very interesting however.
Let me focus on a few more points : - - The hardware can't really be extended any more. No budget ;-( - - the VM will be mostly few IO systems : - -- WS2003 with Trend Officescan, WSUS (for 300 XP) and RDP - -- Solaris10 with SRSS 4.2 (Sunray server) (File and DB servers won't move in a nearby future to VM+SAN) I thought -but could be wrong- that those systems could afford a high latency IOs data rate. >what you're getting out of it is essentially a 500gb > 15k drive with a high mttdl That's what i wanted, a rock-solid disk area, despite a not-as-good-as-i'd-like random IO. I'll give it a try with sequential tranfer. However, thanks for your answer. > >> 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 > - -- Cordialement. - - Lycée Alfred Nobel,Clichy sous bois http://www.lyceenobel.org KeyID 0x46EA1D16 FingerPrint 997B164F4F606A61E7B1FC61961A821646EA1D16 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkpCjKIACgkQlhqCFkbqHRZ8EwCbBbtEsFOimeiUXFMNRBrJI4uO xuAAnRO8pv3ES2bhIUWfEuyEtp8M1vGl =kRUK -----END PGP SIGNATURE----- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
