On Jul 29, 2008, at 2:24 PM, Chris Cosby wrote: > > > On Tue, Jul 29, 2008 at 5:13 PM, Stefano Pini <[EMAIL PROTECTED]> > wrote: > Hi guys, > we are proposing a customer a couple of X4500 (24 Tb) used as NAS > (i.e. NFS server). > Both server will contain the same files and should be accessed by > different clients at the same time (i.e. they should be both active) > So we need to guarantee that both x4500 contain the same files: > We could simply copy the contents on both x4500 , which is an option > because the "new files" are in a limited number and rate , but we > would really like to use ZFS send & receive commands: > If they are truly limited, something like an rsync or similar. There > was a script being thrown around a while back that was touted as the > Best Backup Script That Doesn't Do Backups, but I can't find it. In > essence, it just created a list of what changed since the last > backup and allowed you to use tar/cpio/cp - whatever to do the backup.
I think zfs send/recv would be a great way to go here - see below. > > > > > AFAIK the commands works fine but generally speaking are there any > known limitations ? > And, in detail , it is not clear if the receiving ZFS file system > could be used regularly while it is in "receiving mode": > in poor words is it possible to read and export in nfs, files from > a ZFS file system while it is receiving update from another ZFS > send ? > First, the zfs send works only on a snapshot. -i sends incremental > snapshots, so you would think that would work. From the zfs man > page, you'll see that during a receive, the destination file system > is unmounted and cannot be accessed during the receive. > > If an incremental stream is received, then the destina- > tion file system must already exist, and its most recent > snapshot must match the incremental stream's source. The > destination file system and all of its child file sys- > tems are unmounted and cannot be accessed during the > receive operation. Actually we don't unmount the file systems anymore for incremental send/recv, see: 6425096 want online 'zfs recv' (read only and read/write) Available since November 2007 in OpenSolaris/Nevada. Coming to a s10u6 near you. eric _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
