OpenSolaris is the only platform that I'm aware of that supports ZFS and has stable, fast iSCSI Target support. (FreeBSD initiators don't even mount iSCSI LUNs

OpenSolaris is the only platform that I'm aware of that supports ZFS and has stable, fast iSCSI Target support. (FreeBSD initiators don't even mount iSCSI LUNs on a reboot. I happen to like FreeBSD anyway, but it's not quite there for iSCSI.) In plain english, OpenSolaris (the right version at least, avoid de-duplication) is the only free platform I'm aware of that will give you a fast, stable, iSCSI server with a file system that's basically impervious to corruption. The only one. Seriously. COMSTAR and ZFS are that big of a deal. They aren't "nice to have"s. They're solutions that allow you to spend a couple grand on a box, put a lot of RAM in it, attach a JBOD, shove in a few SSDs for read-cache and write-logs and you can duplicate the performance million dollar storage systems on the cheap. You can do this with very little effort on commodity hardware. You can start as small as you want and scale as large as you want. You get snapshots, clones and replication with barely any effort. Sun's whole storage strategy (Sun Unified Storage) was built on nothing more than exactly this with a pretty Web interface sitting on top. OpenSolaris is a real pain for a lot of things, but when it comes to storage nothing else comes close (that I'm aware of). Don't be scared that you'll lose an alternative to Linux. OpenSolaris isn't any good as an application host if you're expecting anything close to modern GNU tools. Be scared that you'll lose an alternative to NetApp.