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One thing that's been unclear to me with ZFS: How should I design a ZFS-based storage system for extensibility? From what I've read, it seems like you can't add
by eric_the_read 10y ago
One thing that's been unclear to me with ZFS: How should I design a ZFS-based storage system for extensibility? From what I've read, it seems like you can't add devices to a pool once it's been created. I'd love to create a small-ish NAS right now to store, say, the top 10% of my blu-ray collection, and then incrementally upgrade it over time as I get funds.
- snvzz 10y agoYou can add vdev to pool anytime. Removing them is not as easy, so some planning is necessary.
- eric_the_read 10y agoFor others, I found this, explaining the process: http://alp-notes.blogspot.com/2011/09/adding-vdev-to-raidz-pool.html http://alp-notes.blogspot.com/2011/09/adding-vdev-to-raidz-p... Downside is, you lose a significant chunk of storage (the author measured > 20%), but you can add new storage to a pool online.
- wtallis 10y agoYou can expand a pool one RAID array at a time, but growing one drive at a time isn't really possible except by not using RAID; ZFS doesn't have a true equivalent to the BTRFS rebalance operation.
- qwertyuiop924 10y agohttps://jsosic.wordpress.com/2013/01/01/expanding-zfs-zpool-raid/ https://jsosic.wordpress.com/2013/01/01/expanding-zfs-zpool-...
- eric_the_read 10y agoYeah, I saw that before, but that isn't quite what I wanted, if I'm reading it right. That tells me how to replace all the drives in my array with new ones; I'd prefer to (for instance) start with 4x 4TB drives, and add new ones as my storage needs build up.
- qwertyuiop924 10y agohttp://docs.oracle.com/cd/E19253-01/819-5461/6n7ht6qvk/index.html http://docs.oracle.com/cd/E19253-01/819-5461/6n7ht6qvk/index...
- eric_the_read 10y agoNice! Thanks for that.
- qwertyuiop924 10y agoI don't know if that works on OpenZFS, though. Probably.
- yoasif_ 10y agoThe easiest way to do this is to use mirror vdevs, that way you can add disks two at a time. Of course, you miss out on RAIDZ functionality that way, but that's the simplest setup. I've gone ahead and actually created a new array using btrfs raid10 instead (with an eye towards a RAIDZ2/3 like configuration whenever the btrfs guys get around to fixing it); btrfs allows for online reshaping of the mirroring configuration, so it doesn't have the limitations of ZFS in this instance.
- eric_the_read 10y agoCan you do btrfs with FreeNAS? I didn't think that was available.
- yoasif_ 10y agoNo, you have to go with Linux. I'm using the latest Ubuntu server LTS (since ZFS is also included, and because I'm familiar with Ubuntu). I don't have experience with FreeNAS unfortunately.
- jmporcel 10y agoIf you could, that makes no sense. ZFS is superior.
- cyphar 10y agoUnless you want to reshape your array. Then md-raid is superior. Btrfs's raid implementation has had some pretty bad issues recently and has been declared "experimental" as a result.
- yoasif_ 10y agoThis is inaccurate. Raid56 have always been labeled experimental, but recently, data corruption bugs were found which make it dangerous to use. Other raid levels (raid0, raid1, raid10) work fine and are considered stable -- at least as stable as the filesystem itself. Either way, if you care about the data, you must backup, no matter what fs you use.