Hugo Mills posted on Sat, 01 Aug 2015 22:34:13 +0000 as excerpted: >> Yes and that also puts it in the realm of kernels that weren't >> releasing/deallocating empty chunks; although I don't know if that's a >> factor, if dconvert forcibly deals with this.. > > It does -- you only have to look at the btrfs fi df output to see > that there's no empty block groups (to within 0.1% or so)
Exactly. The allocations are all full. And the fi show says there's little to no room to allocate more, as well. There's room on one device, but that's not going to help except with single, which shouldn't be allocated any more. I'd say... 1) If this fs was created with btrfs-progs v4.1.1, get what you need to retrieve off of it immediately, then blow it away and start over, as the thing isn't stable and all data is at risk. 2) If it wasn't created with progs v4.1.1, the next issue is that kernel, since it's obviously from before raid56 was fully functional (well either that or there's a more serious bug going on). Existing data should at least be reasonably stable, but with raid56 mode being so new, the newer the kernel you're using to work with it, the better. 4.1.x at LEAST, if not 4.2-rc, as we're nearing the end of the 4.2 development cycle. And plan on keeping even better than normal backups and on current on kernels for at least another several kernel cycles, if you're going to use raid56 mode, as while it's complete now, it's going to take a bit to stabilize to the level of the rest of btrfs itself, which of course is stabilizing now, but not really fully stable and mature yet, so the sysadmin's rule that data with any value is backed up, or by definition it's throw-away data, despite any claims to the contrary, continues to apply double on btrfs, compared to more mature and stable filesystems. So definitely upgrade the kernel. Then see where things stand. 3) Meanwhile, based on raid56 mode's newness, I've been recommending that people stay off it until 4.5-ish or so, basically a year after initial nominal full support, unless of course their intent is to be a leading/ bleeding edge testing and report deployment. Otherwise, use raid1 or raid10 mode until then, and evaluate raid56 mode stability around 4.5, before deploying. And if you're one of the brave doing current raid56 deployment, testing and bug reporting in full knowledge of its newness and lack of current stability and maturity, THANKS, it's your work that's helping to stabilize it for others, when they do switch to it. =:^) -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
