AFP is not the same as HFS+. Time Machine will work better with AFP than NFS or SMB/CIFS, but it's still not using native HFS+ unless you are using block storage (even if you use AFP with an HFS+ filesystem).
Time Machine cannot function at all without accessing HFS+ directly. If you are using a network filesystem (AFP, SMB/CIFS or NFS), Time Machine creates a sparse disk image, formatted as HFS+ and stores it on your file-server. It then attaches that disk image as a disk device and mounts it (somewhat like "mdconfig -a -t vnode -f /path/to/disk-image -u 1; mount /dev/md1 /mnt"). It then treats that disk image basically the same way that it treats local attached storage, including creating hard directory links (but all inside the disk image). See man hdiutil (on OS X) for more info, particularly the part about SPARSEBUNDLEs, sparse images backing HFS+ filesystems and band sizes. Even if you use Mac OS 10 Server and create a Time Machine share (which is the best case scenario), it still uses emulated block storage as described above (disk image over AFP on HFS+). I have personally done this and decided that it was not a very good solution. Your milage may very. I know that people do this, but it seems rather silly. If you have the knowledge to use ZFS, use a zvol via iSCSI. It is much more efficient to use a form of network storage that handles block access natively (like iSCSI) instead of accessing emulated block storage via file-sharing protocols that were not designed for such use. ZFS doesn't care what you use it for. If you are using ZFSv28 (I wouldn't use it for critical data on FreeBSD yet) you can even do dedupe and compression on a native HFS+ Time Machine volume (although you would only see the saved space from the perspective of the zpool and make sure you have lots of RAM). On Apr 28, 2011, at 12:33 PM, Chuck Swiger wrote: > On Apr 28, 2011, at 12:17 PM, George Kontostanos wrote: >> I am using TM over smb on a ZFS Raidz1 pool of my fileserver with no >> problems whatsoever. >> >> NAME USED AVAIL REFER MOUNTPOINT >> tank/apple 37.2G 82.8G 37.2G /tank/apple >> >> Oldest backup 14 December 2009 > > SMB aka CIFS is a better choice than NFS, because it supports better locking > (oplocks or "stealable" locks), but it is not as good as AFP for this > particular purpose. Also, ZFS isn't going to be as space efficient at > storing TM backups compared with HFS+, because it doesn't support hard links > to directories. > > Regards, > -- > -Chuck > > > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
