On Wednesday, 7 March 2018 12:58:29 AM AEDT Craig Sanders via luv-main wrote: > 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.
My main workstation has 500G, 240G, and 120G SSDs in a RAID-1 BTRFS configuration. I bought the 120G SSD for that system, the others weren't needed for other systems (the 500G one was from when I learned the difference between M.2 SATA and M.2 NVMe the expensive way). > 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. That only applies as long as none of them fail. > > 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. Well if you don't have a backup you will lose anyway eventually. > 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. That's about $200 cost and some annoyance. Not a big deal. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/ _______________________________________________ luv-main mailing list luv-main@luv.asn.au https://lists.luv.asn.au/cgi-bin/mailman/listinfo/luv-main
