Andrew Lentvorski wrote: > James G. Sack (jim) wrote: >> Andrew Lentvorski wrote: >>> Gus Wirth wrote: >>>> I think what you want is VMware. Do all your computing in a virtual >>>> machine and when you break something roll back to the last known good >>>> snapshot. You can keep lots of snapshots and even branch them for >>>> different tasks. >>> OpenSolaris also has a nice feature which takes a ZFS snapshot of your >>> system before upgrading, upgrades it, and then switches over to the new >>> system. You can revert back to the old snapshot, however, if you want. >>> >> >> How expensive are these snapshots -- are they COW? > > All of ZFS is copy-on-write all the time. So, snapshots are very fast. > >> Presumably you need >> to quiesce the fs (and things like databases) before the snapshot, eh? > > No, the copy-on-write takes care of that as long as the system requests > a proper synchronous barrier. Although, you shouldn't really be mixing > your system volumes with your application volumes.
Ayup on the mixing, thanks for the GOOD reminder! >> I assume VMware snapshots are a different animal -- do their snapshots >> require a restart, maybe? > > No. VMware snapshots are of the *entire* system--including RAM. Thus, > when you revert a "snapshot" you are reverting to an actual earlier > position in time. > > VMWare snapshots tend to be painfully slow. Regards, ..jim -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
