On 11 Mar 2010, at 04:17, Erik Trimble wrote: > Matt Cowger wrote: >> On Mar 10, 2010, at 6:30 PM, Ian Collins wrote: >> >> >>> Yes, noting the warning. >> >> Is it safe to execute on a live, active pool? >> >> --m >> > Yes. No reboot necessary. > > The Warning only applies to this circumstance: if you've upgraded from an > older build, then upgrading the zpool /may/ mean that you will NOT be able to > reboot to the OLDER build and still read the now-upgraded zpool. > > > So, say you're currently on 111b (fresh 2009.06 build). It has zpool > version X (I'm too lazy to look up the actual version numbers now). You now > decide to live on the bleeding edge, and upgrade to build 133. That has > zpool version X+N. Without doing anything, all pool are still at version X, > and everything can be read by either BootEnvironment (BE). However, you want > the neat features in zpool X+N. You boot to the 133 BE, and run 'zpool > upgrade' on all pools. You now get all those fancy features, instantly. > Naturally, these new features don't change any data that is already on the > disk (it doesn't somehow magically dedup previously written data). HOWEVER, > you are now in the situation where you CAN'T boot to the 111b BE, as that > version doesn't understand the new pool format. > > Basically, it boils down to this: upgrade your pools ONLY when you are sure > the new BE is stable and working for you, and you have no desire to revert to > the old pool. I run a 'zpool upgrade' right after I do a 'beadm destroy > <oldBE>'
I'd also add that for disaster recovery purposes you should also have a live CD handy which supports your new zpool version. Cheers, Chris _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
