I did it.  I finally got Time Machine working over iSCSI on my OpenSolaris RAIDZ1 ZFS pool:

For the most part, I followed the instructions here:

http://opensolaris.org/os/project/qosug/how-tos/zfs_iscsi_integration

Step #6 didn’t make sense to me (not sure what I was supposed to do), so I skipped it.

It also wasn’t quite as plug and play as the article suggests.  Here’s some of the problems I had to overcome:

1. My SCSI card wasn’t recognized by OpenSolaris.  This Google Group thread really helped.  Basically, I had to get the SUNWadp driver from a different Solaris distribution (I used SXCE).  I’m still not clear about how pkgadd works with a directory, so I just copied the uncompressed driver to /var/spool/pkg then ran pfexec pkgadd.  I also found (via dmesg after rebooting) that the driver is 32-bit only, so I had to remove $ISADIR from /rpool/boot/grub/menu.lst to boot in 32-bit mode.  I also found out that’s not really desirable with ZFS as it favors 64-bit but it’ll have to do until I can find a newer SCSI card.
2. I had my ZPOOL created, but kept getting errors when I tried to turn on iSCSI.  I then proceeded to try to install the COMSTAR iSCSI target pkg, which didn’t work.  I found out it was already installed and all I needed to do was enable the service.  Doh!  I’m still not clear on CLI-fu on OpenSolaris, so I used the Services GUI to do this.  I actually looked for the command to do it via CLI, but it seems to have changed quite a bit from release to release.  I was also getting impatient and wanted results!  :)  The good thing is, the GUI shows you the command, so it’s a good way to learn.

That’s it!  Thankfully once I had done that, I was able to connect to the target via the globalSAN iSCSI Initiator for OS X.  I actually expected it not to work, but it worked without a hitch!  I was able to format the ZVOL HFS+ so Time Machine could use it, and my backups began!  This was much faster performance-wise than AFP on Linux, and I didn’t have to trick time machine into using it!

Things I still need to do:

1. Figure out how to allocate the rest of the ZPOOL and share it via CIFS & hopefully AFP!  How do I tell ZFS to use the rest of the pool?  zfs create -s -V …
2. Get better with Solaris/OpenSolaris CLI.  Coming from Linux… it’s different.
3. Find a supported SCSI card and use 64-bit.
4. Figure out how to automatically mount/unmount the volume on my laptop for when I get to work or leave.  The trigger should be whenever I plug in my ethernet cable, but ONLY for that location.  Tricky…
5. Figure out iSCSI authentication, such as CHAP.

iSCSI uses a LOT of TCP overhead, so keep that in mind if you’re doing it yourself.  I have a gigabit switch in my office that all my machines hook into, so that traffic is kept off the main network.  I would not try it over wireless (if that’s even possible).

The more I learn Sun, the more I’m realizing it’s not really for the “latest and greatest” technologies, but rather a rock-solid stability.  OpenSolaris seems to be trying to bridge that gap, so I’m looking forward to seeing where it goes.