在将我的服务器从 Debian Jessie 升级到 Debian Stretch 之前，我创建了 rootfs 的 LVM2 快照 ( /)。
根据多种工具，我的存储目前的样子如下。/dev/intraid/root是我原来的rootfs，/dev/intraid/root-snapshot是快照：
$ sudo lvdisplay
--- Logical volume ---
LV Path /dev/intraid/root
LV Name root
VG Name intraid
LV UUID 0d5hwZ-07Lv-3Yxb-cff3-95za-Rrcx-9y6eQv
LV Write Access read/write
LV Creation host, time newsrv, 2015-05-26 09:32:04 +0800
LV snapshot status source of
root-snapshot [active]
LV Status available
# open 1
LV Size 3.18 TiB
Current LE 834465
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Logical volume ---
LV Path /dev/intraid/root-snapshot
LV Name root-snapshot
VG Name intraid
LV UUID A9sjTI-gcV8-WTLi-wZ0I-J7O6-4hdc-AQSxZj
LV Write Access read/write
LV Creation host, time newsrv, 2018-05-04 19:25:12 +0800
LV snapshot status active destination for root
LV Status available
# open 1
LV Size 3.18 TiB
Current LE 834465
COW-table size 180.00 GiB
COW-table LE 46080
Allocated to snapshot 57.08%
Snapshot chunk size 4.00 KiB
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:3
$ lsblk -t
sdf 0 4096 0 4096 512 1 cfq 128 128 0B
├─sdf1 0 4096 0 4096 512 1 cfq 128 128 0B
├─sdf2 0 4096 0 4096 512 1 cfq 128 128 0B
│ └─md0 0 4096 0 4096 512 1 128 128 0B
│ ├─intraid-root-real 0 4096 0 4096 512 1 128 128 0B
│ │ ├─intraid-root 0 4096 0 4096 512 1 128 128 0B
│ │ └─intraid-root--snapshot 0 4096 0 4096 512 1 128 128 0B
│ └─intraid-root--snapshot-cow 0 4096 0 4096 512 1 128 128 0B
│ └─intraid-root--snapshot 0 4096 0 4096 512 1 128 128 0B
└─sdf3 0 4096 0 4096 512 1 cfq 128 128 0B
sdg 0 4096 0 4096 512 1 cfq 128 128 0B
├─sdg1 0 4096 0 4096 512 1 cfq 128 128 0B
├─sdg2 0 4096 0 4096 512 1 cfq 128 128 0B
│ └─md0 0 4096 0 4096 512 1 128 128 0B
│ ├─intraid-root-real 0 4096 0 4096 512 1 128 128 0B
│ │ ├─intraid-root 0 4096 0 4096 512 1 128 128 0B
│ │ └─intraid-root--snapshot 0 4096 0 4096 512 1 128 128 0B
│ └─intraid-root--snapshot-cow 0 4096 0 4096 512 1 128 128 0B
│ └─intraid-root--snapshot 0 4096 0 4096 512 1 128 128 0B
└─sdg3 0 4096 0 4096 512 1 cfq 128 128 0B
$ sudo blkid
/dev/sdf1: UUID="C622-1FAD" TYPE="vfat" PARTUUID="3d63a1ce-dd19-4396-9f9c-7894a4e9b256"
/dev/sdf2: UUID="3eb2349d-df83-c9a5-7151-9bdcb40449f8" UUID_SUB="b04a81da-8279-8ade-130d-65478f415085" LABEL="newsrv:0" TYPE="linux_raid_member" PARTUUID="607b2070-1de3-4e58-89f4-401d3144d52c"
/dev/sdf3: UUID="9b8fb3d2-4bb3-4a48-8b26-23af503b9d28" TYPE="swap" PARTUUID="8778cdc1-1fd8-4af0-b7a0-9dbca0d137fa"
/dev/sdg1: UUID="C623-571D" TYPE="vfat" PARTUUID="56f5dc2f-0562-4590-a54d-8c705dfef79f"
/dev/sdg2: UUID="3eb2349d-df83-c9a5-7151-9bdcb40449f8" UUID_SUB="8370e4ce-6b8b-5cdf-1043-60e748758898" LABEL="newsrv:0" TYPE="linux_raid_member" PARTUUID="ee82035a-6e8a-4bb8-9828-336ee85d3afd"
/dev/sdg3: UUID="a3062d00-d91b-490d-b366-7cfbfb42c09d" TYPE="swap" PARTUUID="fb6b3047-bfd4-4502-97ba-1a58197e75f4"
/dev/md0: UUID="44gLpv-engQ-I0KW-VJ0e-2Q6Z-OCeI-m0HSWq" TYPE="LVM2_member"
/dev/mapper/intraid-root: UUID="a96458d1-87d6-4cf6-a004-7b8ceb3ae31f" TYPE="xfs"
/dev/mapper/intraid-root--snapshot: UUID="a96458d1-87d6-4cf6-a004-7b8ceb3ae31f" TYPE="xfs"
$ mount
/dev/mapper/intraid-root on / type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mapper/intraid-root on /srv/matlab_chroot/usr/local/MATLAB type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mapper/intraid-root on /srv/matlab_chroot/shared_home type xfs (rw,relatime,attr2,inode64,noquota)
/dev/sdf1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro)
/dev/mapper/intraid-root on /srv/matlab_chroot/mnt/nethome-new type xfs (rw,relatime,attr2,inode64,noquota)
$ sudo lsof /dev/mapper/intraid-root--snapshot
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
grub-moun 218357 root 3r BLK 253,3 0x32ee7fe0000 2115 /dev/mapper/../dm-3
$ sudo lsof /dev/intraid/root-snapshot
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
grub-moun 218357 root 3r BLK 253,3 0x32ee7fe0000 2115 /dev/intraid/../dm-3
$ sudo lsof /dev/mapper/intraid-root--snapshot-cow
$ sudo lsof /dev/mapper/intraid-root-real
$ findmnt
TARGET SOURCE FSTYPE OPTIONS
/ /dev/mapper/intraid-root xfs rw,relatime,attr2,inode64,noquota
├─/srv/matlab_chroot/usr/local/MATLAB /dev/mapper/intraid-root[/usr/local/MATLAB]
│ xfs rw,relatime,attr2,inode64,noquota
├─/srv/matlab_chroot/shared_home /dev/mapper/intraid-root[/home] xfs rw,relatime,attr2,inode64,noquota
├─/srv/matlab_chroot/mnt/nethome-new /dev/mapper/intraid-root[/mnt/nethome-new]
请注意，快照不是根据 的输出安装的mount。
但是，当我尝试删除快照时，我收到以下消息：
$ sudo lvremove -f intraid/root-snapshot
Logical volume intraid/root-snapshot in use.
我该怎么做才能放弃它？
答案1
您的mount命令输出显然已被修剪。不幸的是，您似乎切断了与问题相关的内容。
看起来进程 218357 可能仍在访问快照。从部分命令名称来看，它似乎是grub-mount.由于它使用FUSE和GRUB的驱动程序来访问文件系统，因此它直接将LV设备作为“原始磁盘设备”进行访问。
出于同样的原因，它不像常规安装座那样可见。我刚刚安装了我的/dev/sda1，grub-mount它看起来像这样：
# grub-mount /dev/sda1 /mnt
# mount
[...other mount points omitted...]
grub-mount on /mnt type fuse.grub-mount (rw,nosuid,nodev,relatime,user_id=0,group_id=0)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
请注意，grub-mounted 文件系统显示为类型fuse.grub-mount，并且该行并不指示实际安装了哪个磁盘设备。fusectl on /sys/fs/fuse/connections当使用基于 FUSE 的挂载条目时，总是出现第二个挂载条目：它是 FUSE 接口的一部分。
因此，首先找到并卸载它，grub-mount因为它似乎使快照设备保持打开状态。卸载后，您应该能够使用最初尝试的命令正常删除快照。