Hi, With dual-Xeon, 4GB of Ram (will be 8GB in a couple of weeks), two PCI-X 3Ware cards 7 Sata disks (750G & 1T) over FreeBSD 8.0 (But i think it's OS independant), i made some tests.
The disks are exported as JBOD, but i tried enabling/disabling write-cache . I tried with UFS and ZFS on the same disk and the difference is overwhelming. With a 1GB file (greater than the ZFS cache ?): With Writecache disabled UFS time cp /mnt/ufs/rnd /mnt/ufs/rnd2 real 2m58.073s ZFS time cp /zfs/rnd /zfs/rnd2 real 4m33.726s On the same card with WCache enabled UFS time cp /mnt/ufs/rnd /mnt/ufs/rnd2 real 0m31.406s ZFS time cp /zfs/rnd /zfs/rnd2 real 1m0.199s So, despite the fact that ZFS can be twice slower than UFS, it is clear that Write-Cache have to be enabled on the controller. Any drawback (except that without BBU, i've got a pb in case of power loss) in enabling the WC with ZFS ? Thanks. Best regards. -- Lycée Maximilien Perret, Alfortville _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
