covici posted on Sat, 10 Oct 2015 19:08:16 -0400 as excerpted: > covici@xxxxxxxxxxxxxx wrote: > >> Lionel Bouton <lionel+ceph@xxxxxxxxxxx> wrote: >> >> > Le 10/10/2015 18:55, covici@xxxxxxxxxxxxxx a écrit : >> > > [...] >> > > But do you folks have any idea about my original question, this >> > > leads me to think that btrfs is too new or something. >> > >> > I've seen a recent report of a problem with btrfs-progs 4.2 confirmed >> > as a bug in mkfs. As you created the filesystem with it, it could be >> > the problem. > > I do have 4.2.2, I could go to, would that be better? btrfs-progs-4.2.2 does indeed have the mkfs.btrfs fixes for the bug in question. You should be fine remaking the filesystem with it. If you created the filesystem with the buggy mkfs.btrfs, AFAIK, current 4.2.2 btrfs check can detect the error, but can't fix it. Blowing away the filesystem and recreating is the only known fix at this time, and filesystems created with the buggy version are not safe and could blow up at any time, so it's best to be rid of them and onto something more stable as soon as possible. I can't help with the subvolumes bit, however, because while I'm on gentoo/~amd64 here too, also with systemd... I don't use subvolumes, as to me it's simply putting too many eggs in one filesystem basket. Instead, I prefer multiple separate btrfs filesystems, each on their own partitions. My / includes most of what packages install, including /usr and /var but not /var/log. It's 8 GiB in size, under half used. /home is separate, the repos tree (gentoo and overlays) along with ccache, binpackages, the kernel tree, etc, are together on a separate partition, /var/log is separate (and tiny, half a GiB), etc. I keep / mounted read-only by default, so have the parts of / var/lib that must be runtime-writable symlinked to subdirs of /home/var, with /home of course mounted writable, but other than that and some /var/ log/ subdirs, anything that's installed by a package is on /, a lesson I learned the hard way when I had to recover from backups where /, /usr and /var were from backups taken on different dates and thus not synchronized with what portage /thought/ was installed based on /var/db/ pkg. Not saying that's best for you, but it's a solution that I've found works very well for me, and the relative small 8 GiB size of / makes it easy to have backup copies of it that I can boot, should my working / take a dump. But if it's all on the same filesystem, as it is with subvolumes, and that filesystem takes a dump... it's all gone at once! That's not something I want to happen, so I vastly prefer the independent filesystems, but with everything (but the limited exceptions mentioned above) the package manager deals with on the same one, so it all stays synced and is backed up as a single unit, which after all remains reasonably small, 8 GiB, less than half used. -- 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
