On Wed, Dec 10, 2008 at 12:46:40PM -0600, Gary Mills wrote: > On the server, a variety of filesystems can be created on this virtual > disk. UFS is most common, but ZFS has a number of advantages over > UFS. Two of these are dynamic space management and snapshots. There > are also a number of objections to employing ZFS in this manner. > ``ZFS cannot correct errors'', and ``you will lose all of your data'' > are two of the alarming ones. Isn't ZFS supposed to ensure that data > written to the disk are always correct? What's the real problem here?
ZFS has very strong error detection built-in, and for mirrored and RAID-Zed pools can recover from errors automatically as long as there's a mirror left or enough disks in RAID-Z left to complete the recovery. ZFS can also store multiple copies of data and metadata even in non-mirrored/non-RAID-Z pools. ZFS always leaves the filesystem in a consistent state, provided the drives aren't lying. Whoever is making those objections is misinformed. > This is a split responsibility configuration where the storage device > is responsible for integrity of the storage and ZFS is responsible for > integrity of the filesystem. How can it be made to behave in a > reliable manner? Can ZFS be better than UFS in this configuration? It does. It is. > Is a different form of communication between the two components > necessary in this case? No. Note that you'll generally be better off using RAID-Z than HW RAID-5. Nico -- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
