On Tue, Mar 06, 2018 at 11:22:17PM +1100, Russell Coker wrote:
If you have any sort of enterprise use then you will have matched pairs.
I've been doing that at home for a long time. I resigned myself many years ago to always paying double the going price for storage because I always want RAID-1/mirrored-pairs. It means I have to put off some upgrades until I can afford, e.g. two x 4TB or two x 8TB drives instead of just one, but it is, IMO, worth it. OTOH, it does mean that when I upgrade my main machine, I have matched pairs of older drives to distribute amongst other machines. I'll probably be replacing a 4 x 1TB RAIDZ-1 pool with a pair of 8TB drives later this year. The 1TB drives are still working, so I'll split them into two pairs and add them to two other machines.
For home use it's pretty common to just use whatever you have available. If you have a home BTRFS RAID-1 setup you can just add a new disk at any time and after a balance operation the RAID-1 capacity will have increased by half the size of that disk. I have a spare 4TB disk sitting around for when I need an extra 2TB of usable space in my home server.
yep, that's one of the advantages of btrfs. It's also a disadvantage because it encourages you to mix old drives, possibly failing or at least close to or maybe beyond their expected lifespan, with new ones. That's not a risk I'd take with storage devices...at least, not for any important data that I didn't have backed up.
RE: CDDL vs GPL
Oh well my clients will be safe, their position is that they trust Canonical and will keep using it until/unless advised otherwise.
Your clients aren't at any risk - they haven't distributed CDDL+GPL binaries. GPL & CDDL only restrict distribution, not use. At most, they might have to compile their own spl and zfs modules (apt-get install spl-dkms zfs-dkms should be all that's needed). Or get you to do it. craig -- craig sanders <cas@taz.net.au>