[EMAIL PROTECTED] said: > . . . > ZFS filesystem [on StorageTek 2530 Array in RAID 1+0 configuration > with a 512K segment size] > . . . > Comparing run 1 and 3 shows that ZFS is roughly 20% faster on > (unsynchronized) writes versus UFS. What's really surprising, to me at least, > is that in cases 3 and 5, for example, ZFS becomes almost 400% slower on > synchronized writes versus UFS. I realize that the ZFS-on-RAID setup has a > "safety" penalty, but should it really be 400% slower than UFS? If not, then > I'm hoping for suggestions on how to get some better ZFS performance from > this setup.
I don't think there is any "safety penalty" for ZFS on RAID, unless you're comparing it to ZFS on JBOD. On RAID without ZFS-level redundancy, you only give up ZFS-level self-healing. The sync-write issue here is likely similar to that of an NFS server. If all of your ZFS pools on this system are on battery-backed cache RAID (e.g. the 2530 array), then you could safely set zfs_nocacheflush=1. If not, then there should be a way to set the 2530 to ignore the ZFS sync-cache requests. Give it a try and let us all know how it affects your tests. We've got a 2530 here doing Oracle duty, but it's so much faster than the storage it replaced that we haven't bothered doing any performance tuning. Regards, Marion _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
