无法删除btrfs快照
我无法删除“apt-snapshot-release-upgrade-saucy-2013-10-19_00：52：26”btrfs快照。 以下是详细信息：
root@cioco:~# btrfs subvolume list -s / ID 261 gen 246 cgen 245 top level 5 otime 2013-10-19 00:52:26 path @apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 root@cioco:~# btrfs subvolume list / ID 256 gen 334584 top level 5 path @ ID 258 gen 334134 top level 5 path @home ID 261 gen 246 top level 5 path @apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 ID 267 gen 334580 top level 256 path var/lib/lxc/mythtv/rootfs ID 268 gen 334584 top level 256 path var/lib/lxc/jira/rootfs ID 278 gen 279278 top level 256 path var/lib/lxc/michele/rootfs root@cioco:~# grep btrfs /proc/self/mountinfo 20 1 0:16 /@ / rw,relatime - btrfs /dev/sda2 rw,compress=zlib,space_cache 39 20 0:16 /@home /home rw,relatime - btrfs /dev/sda2 rw,compress=zlib,space_cache root@cioco:~# btrfs subvolume delete /@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 ERROR: error accessing '/@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26' 但是我可以删除由我创建的快照：
root@cioco:~# btrfs subvolume snapshot / root-snap Create a snapshot of '/' in './root-snap' root@cioco:~# btrfs subvolume list -s / ID 261 gen 246 cgen 245 top level 5 otime 2013-10-19 00:52:26 path @apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 ID 309 gen 334592 cgen 334592 top level 256 otime 2014-03-31 02:19:08 path root/root-snap root@cioco:~# btrfs subvolume delete /root/root-snap Delete subvolume '/root/root-snap'
EDIT1：内核日志中没有记录任何内容：
root@cioco:~# dmesg -c >/dev/null root@cioco:~# btrfs subvolume delete /@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 ERROR: error accessing '/@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26' root@cioco:~# dmesg root@cioco:~#
但是strace给出了一个暗示：
root@cioco:~# strace btrfs subvolume delete /@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 ... stat("/@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26", 0x7fffe88ebb60) = -1 ENOENT (No such file or directory) write(2, "ERROR: error accessing '/@apt-sn"..., 82ERROR: error accessing '/@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26' ) = 82
编辑2：我已经安装了卷…
root@cioco:~# mkdir /snapshot root@cioco:~# mount /dev/sda2 /snapshot -o subvol=/@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 root@cioco:~# grep btrfs /proc/self/mountinfo 20 1 0:16 /@ / rw,relatime - btrfs /dev/sda2 rw,compress=zlib,space_cache 39 20 0:16 /@home /home rw,relatime - btrfs /dev/sda2 rw,compress=zlib,space_cache 61 20 0:16 /@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 /snapshot rw,relatime - btrfs /dev/sda2 rw,compress=zlib,space_cache root@cioco:~# btrfs subvolume delete /snapshot/ Delete subvolume '//snapshot' ERROR: cannot delete '//snapshot' - Invalid argument root@cioco:~# strace btrfs subvolume delete /snapshot/ ... stat("/snapshot", {st_mode=S_IFDIR|0755, st_size=230, ...}) = 0 brk(0) = 0x2206000 brk(0x2228000) = 0x2228000 lstat("/snapshot", {st_mode=S_IFDIR|0755, st_size=230, ...}) = 0 stat("/", {st_mode=S_IFDIR|0755, st_size=242, ...}) = 0 openat(AT_FDCWD, "/", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3 fstat(1, {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 23), ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fd8ad2ae000 write(1, "Delete subvolume '//snapshot'\n", 30Delete subvolume '//snapshot' ) = 30 ioctl(3, BTRFS_IOC_SNAP_DESTROY, 0x7fff5f1e5878) = -1 EINVAL (Invalid argument) close(3) = 0 write(2, "ERROR: cannot delete '//snapshot"..., 53ERROR: cannot delete '//snapshot' - Invalid argument ) = 53 ... root@cioco:~# dmesg [3172764.459166] device label cioco-root devid 1 transid 336213 /dev/sda2
Edit3：解决方案
root@cioco:~# mount /dev/sda2 /btrfs-root/ root@cioco:~# ls -l /btrfs-root/ total 0 drwxr-xr-x 1 root root 262 Apr 1 08:31 @ drwxr-xr-x 1 root root 230 Oct 16 22:53 @apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26 drwxr-xr-x 1 root root 6 Oct 16 22:13 @home root@cioco:~# btrfs subvolume delete /btrfs-root/@apt-snapshot-release-upgrade-saucy-2013-10-19_00\:52\:26/ Delete subvolume '/btrfs-root/@apt-snapshot-release-upgrade-saucy-2013-10-19_00:52:26' root@cioco:~# dmesg [41113.537617] device label cioco-root devid 1 transid 337615 /dev/sda2
任何帮助，将不胜感激。
快照存在于文件系统的实际根目录中，而不是您在/中安装的快照。 您在/中安装了/ @ subvolume，因此没有具有该名称的此类文件。 您必须在某处安装实际根卷并使用该路径引用快照。
或者您可以使用apt-btrfs-snapshot delete 。