On Wed, Jun 20, 2007 at 12:23:18PM -0400, Torrey McMahon wrote: > James C. McPherson wrote: > >Roshan Perera wrote: > >> > >>>But Roshan, if your pool is not replicated from ZFS' point of view, > >>>then all the multipathing and raid controller backup in the world will > >>>not make a difference. > >> > >>James, I Agree from ZFS point of view. However, from the EMC or the > >>customer point of view they want to do the replication at the EMC level > >>and not from ZFS. By replicating at the ZFS level they will loose some > >>storage and its doubling the replication. Its just customer use to > >>working with Veritas and UFS and they don't want to change their > >>habbits. > >>I just have to convince the customer to use ZFS replication. > > > >that's a great shame because if they actually want > >to make use of the features of ZFS such as replication, > >then they need to be serious about configuring their > >storage to play in the ZFS world.... and that means > >replication that ZFS knows about. > > Also, how does replication at the ZFS level use more storage - I'm > assuming raw block - then at the array level?
SAN storage generally doesn't work that way. They use some magical redundancy scheme, which may be RAID-5 or WAFL, from which the Storage Administrator carves out virtual disks. These are best viewed as an array of blocks. All disk administration, such as replacing failed disks, takes place on the storage device without affecting the virtual disks. There's no need for disk administration or additional redundancy on the client side. If more space is needed on the client, the Storage Administrator simply expands the virtual disk by extending its blocks. ZFS needs to play nicely in this environment because that's what's available in large organizations that have centralized their storage. Asking for raw disks doesn't work. -- -Gary Mills- -Unix Support- -U of M Academic Computing and Networking- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
