tradeoffs of iSCSI vs. AFP when using Time Machine with a NAS?

Question

I'm setting up a home NAS device (Synology DS409) that I'm planning to use for Time Machine backups (amongst other things).

What are the tradeoffs between using iSCSI or AFP to mount the backup volume?

The Synology wiki suggests that iSCSI is better if the Mac will be frequently disconnected from the network or sleeping, from the point of view of the volume automatically remounting. What about filesystem consistency? Given that unplugging a USB drive without properly unmounting it often requires the Time Machine volume to be repaired, would iSCSI have the same issues?

Answer 1

That's strange, because I always thought iSCSI was not friendly in terms of being disconnected from the network. When I was doing Time Machine backups to an OpenSolaris ZFS box via iSCSI, I had to remember to manually unmount the volume before I put the laptop to sleep or disconnected from the network. If I didn't I got an error message, and I think I had problems with getting it reconnected. I'm using AFP now, and I feel it's more disconnection friendly.

Answer 2

I use Time machine with an iSCSI Target(D-Llink DSN-1100) all the time. Disconnecting and reconnecting a volume will not have ill effects on the volume or time machine.

Answer 3

I think your biggest drawback between the two is when recovering... i used iSCSI for TimeMachine before, and it worked grand for backing up, but when i tried recovering from the Lion DVD, it would not see the drive. I had to install Lion manually, then the iSCSI initiator, and then recover files i needed... With AFP, in theory, you should be able to install Lion (or any other OSX for that matter) and then select your backup location and your golden...