我在LVM LV之上的LUKS上有一个500GiB ext4文件系统.我想将LV的大小调整为100GiB.我知道如何在LVM LV之上调整ext4的大小,但我该如何处理LUKS卷呢？
mgorven@moab:~% sudo lvdisplay /dev/moab/backup --- Logical volume --- LV Name /dev/moab/backup VG Name moab LV UUID nQ3z1J-Pemd-uTEB-fazN-yEux-nOxP-QQair5 LV Write Access read/write LV Status available # open 1 LV Size 500.00 GiB Current LE 128000 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 2048 Block device 252:3 mgorven@moab:~% sudo cryptsetup status backup /dev/mapper/backup is active and is in use. type: LUKS1 cipher: aes-cbc-essiv:sha256 keysize: 256 bits device: /dev/mapper/moab-backup offset: 3072 sectors size: 1048572928 sectors mode: read/write mgorven@moab:~% sudo tune2fs -l /dev/mapper/backup tune2fs 1.42 (29-Nov-2011) Filesystem volume name: backup Last mounted on: /srv/backup Filesystem UUID: 63877e0e-0549-4c73-8535-b7a81eb363ed Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags: signed_directory_hash Default mount options: (none) Filesystem state: clean with errors Errors behavior: Continue Filesystem OS type: Linux Inode count: 32768000 Block count: 131071616 Reserved block count: 0 Free blocks: 112894078 Free inodes: 32044830 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 992 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 8192 Inode blocks per group: 512 RAID stride: 128 RAID stripe width: 128 Flex block group size: 16 Filesystem created: Sun Mar 11 19:24:53 2012 Last mount time: Sat May 19 13:29:27 2012 Last write time: Fri Jun 1 11:07:22 2012 Mount count: 0 Maximum mount count: 100 Last checked: Fri Jun 1 11:03:50 2012 Check interval: 31104000 (12 months) Next check after: Mon May 27 11:03:50 2013 Lifetime writes: 118 GB Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 required extra isize: 28 Desired extra isize: 28 Journal inode: 8 Default directory hash: half_md4 Directory Hash Seed: 383bcbc5-fde9-4720-b98e-2d6224713ecf Journal backup: inode blocks
解决方法
LUKS实际上并不存储设备的大小 – 它只是在打开卷时发现它.因此,只有在此过程中未关闭并重新打开音量(例如,进行在线增长)时才会发挥作用.在这种情况下,需要重新发现开放卷的大小.
要缩小音量,请使用以下过程：
>使用umount卸载文件系统
>使用resize2fs调整文件系统的大小
>使用cryptsetup luksClose关闭LUKS卷
>使用lvreduce或lvresize调整LV的大小
>使用cryptsetup luksOpen打开LUKS卷
>使用mount挂载文件系统
您还可以省略luksClose和luksOpen步骤,并在调整LV大小后使用cryptsetup resize.还要记住,LUKS使用一些额外的空间来存储元数据,因此LV需要比文件系统略大.我通常会将文件系统的大小调整得更小,然后在调整LV大小后再次增大它.
如果您正在扩展文件系统并希望在线进行,则可以使用以下过程：
>使用lvextend或lvresize调整LV的大小>使用cryptsetup resize更新打开的LUKS卷的大小>使用resize2fs扩展文件系统
