屑俺日記

☆ マウントしたまま拡大

Debian StretchのLVMにて。
まずは事前準備。100Mの論理ボリュームを確保、 ext4でフォーマット、マウント。

$ sudo pvcreate /dev/sda1
  Physical volume "/dev/sda1" successfully created.
 
$ sudo pvs
  PV         VG Fmt  Attr PSize   PFree
  /dev/sda1     lvm2 ---  953.00m 953.00m
 
$ sudo vgcreate vg_1 /dev/sda1
  Volume group "vg_1" successfully created
 
$ sudo lvcreate -L 100M vg_1 -n lv_1
  Logical volume "lv_1" created.
 
$ sudo mkfs -t ext4 /dev/vg_1/lv_1
mke2fs 1.43.3 (04-Sep-2016)
Discarding device blocks: done         
Creating filesystem with 102400 1k blocks and 25688 inodes
Filesystem UUID: d97242e7-ce46-40fa-9d05-4e0d52a7ef9b
Superblock backups stored on blocks:
        8193, 24577, 40961, 57345, 73729
 
Allocating group tables: done 
Writing inode tables: done 
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done 
 
$ sudo mount /dev/vg_1/lv_1 /media/temp/

データを置いておく。

$ sudo dd if=/dev/zero of=10M.img bs=1M count=10        
10+0 レコード入力
10+0 レコード出力
10485760 bytes (10 MB, 10 MiB) copied, 0.0090295 s, 1.2 GB/s
 
$ ls -l
合計 10252
-rw-r--r-- 1 root root 10485760  1月 26 10:36 10M.img
drwx------ 2 root root    12288  1月 26 10:35 lost+found
 
$ df -h | grep temp
/dev/mapper/vg_1-lv_1    93M   12M   75M   14% /media/temp

umountせずにlvextend(8)とresize2fs(8)で200Mに拡大。

$ sudo lvextend -L 200M /dev/vg_1/lv_1
  Size of logical volume vg_1/lv_1 changed from 100.00 MiB 
(25 extents) to 200.00 MiB (50 extents).
  Logical volume vg_1/lv_1 successfully resized.
 
$ sudo resize2fs /dev/vg_1/lv_1 200M
resize2fs 1.43.3 (04-Sep-2016)
Filesystem at /dev/vg_1/lv_1 is mounted on /media/temp; \
on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 2
The filesystem on /dev/vg_1/lv_1 is now 204800 (1k) blocks long.

最終結果。

$ df -h | grep temp
/dev/mapper/vg_1-lv_1   190M   12M  168M    7% /media/temp

ただし現状、縮小の方はumountしないとできないっぽい。