-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 If I remember correctly, ESX always uses synchronous writes over NFS. If so, adding a dedicated log device (such as a DDRdrive) might help you out here. You should be able to test it by disabling the ZIL for a short while and see if performance improves (http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Disabling_the_ZIL_.28Don.27t.29). I'm not sure how reliable the DDRdrive is in practice, but in theory it should be much better than an SSD, since DRAM doesn't wear.
- -- Saso On 08/27/2010 07:04 AM, Mark wrote: > We are using a 7210, 44 disks I believe, 11 stripes of RAIDz sets. When I > installed I selected the best bang for the buck on the speed vs capacity > chart. > > We run about 30 VM's on it, across 3 ESX 4 servers. Right now, its all > running NFS, and it sucks... sooo slow. > > iSCSI was no better. > > I am wondering how I can increase the performance, cause they want to add > more vm's... the good news is most are idleish, but even idle vm's create a > lot of random chatter to the disks! > > So a few options maybe... > > 1) Change to iSCSI mounts to ESX, and enable write-cache on the LUN's since > the 7210 is on a UPS. > 2) get a Logzilla SSD mirror. (do ssd's fail, do I really need a mirror?) > 3) reconfigure the NAS to a RAID10 instead of RAIDz > > Obviously all 3 would be ideal , though with a SSD can I keep using NFS for > the same performance since the R_SYNC's would be satisfied with the SSD? > > I am dreadful of getting the OK to spend the $$,$$$ SSD's and then not get > the performance increase we want. > > How would you weight these? I noticed in testing on a 5 disk OpenSolaris, > that changing from a single RAIDz pool to RAID10 netted a larger IOP increase > then adding an Intel SSD as a Logzilla. That's not going to scale the same > though with a 44 disk, 11 raidz striped RAID set. > > Some thoughts? Would simply moving to write-cache enabled iSCSI LUN's > without a SSD speed things up a lot by itself? -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkx3gMQACgkQRO8UcfzpOHDL7ACfW43C6lkMD389j/vmldqMDK1f 1H0AoNFdhgHfWKCCMaJQ2DJACpkQicU7 =KIyA -----END PGP SIGNATURE----- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
