I'm looking for some infos/official docs/howto for migrating boot disks in a production enviroment server from internal disks to SAN on Solaris 10. It's possible for every kind of hw? It's also possible in a Sun Cluster enviroment?
It's supported, the only tricky part is determining the path to add as the boot device. You note using Solaris 10, so the easiest method is going to be creating an alternate boot environment with lucreate and booting to it. If you're already using ZFS, you could attach as SAN LUN to the internal zpool to create a mirror.
Using your boot drive off a SAN LUN works very nicely and has a number of benefits. One of which shortening the time of installing the latest CPU set of patches.
I've used SAN booting with and without Sun Cluster.
Just remember to turn on mpxio, and I also reco adding both the primary and alternate paths to the boot device.