linux怎样无损调整分区大小

思路：把home分区的空间划一部分到root分区

# 设置home分区大小为200G，释放300G空间 $ lvreduce -L 200G /dev/centos/home # 将空闲空间扩展到root分区 $ lvextend -l +100%FREE /dev/centos/root # 使用XFS文件系统自带的命令集增加分区空间 $ xfs_growfs /dev/mapper/centos-root

实例

situation

挂载在根目录的分区 /dev/mapper/centos-root 爆满，占用100%

$ df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 50G 50G 19M 100% / devtmpfs 32G 0 32G 0% /dev tmpfs 32G 0 32G 0% /dev/shm tmpfs 32G 2.5G 29G 8% /run tmpfs 32G 0 32G 0% /sys/fs/cgroup /dev/mapper/centos-home 476G 33M 476G 1% /home /dev/sda1 497M 238M 259M 48% /boot tmpfs 6.3G 0 6.3G 0% /run/user/0

analyze

挂载在根目录的分区空间太小，只有50G，而服务器 home 目录为非常用目录，挂在了近500G的空间。

思路：从 centos-home 分区划出300G空间到 centos-root 分区。

operation

1.查看各分区信息

$ lvdisplay --- Logical volume --- LV Path /dev/centos/home LV Name home VG Name centos LV UUID 1fAt1E-bQsa-1HXR-MCE2-5VZ1-xzBz-iI1SLv LV Write Access read/write LV Creation host, time localhost, 2016-10-26 17:23:47 +0800 LV Status available # open 0 LV Size 475.70 GiB Current LE 121778 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:2 --- Logical volume --- LV Path /dev/centos/root LV Name root VG Name centos LV UUID lD64zY-yc3Z-SZaB-dAjK-03YM-2gM8-pfj4oo LV Write Access read/write LV Creation host, time localhost, 2016-10-26 17:23:48 +0800 LV Status available # open 1 LV Size 50.00 GiB Current LE 12800 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0

2.减少/home分区空间

# 释放 /dev/centos/home 分区 300G 的空间 # 命令设置 /dev/centos/home 分区 200G空间 $ lvreduce -L 200G /dev/centos/home WARNING: Reducing active logical volume to 200.00 GiB. THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce centos/home? [y/n]: y Size of logical volume centos/home changed from 475.70 GiB (121778 extents) to 200.00 GiB (51200 extents). Logical volume centos/home successfully resized.

3.增加/root分区空间

$ lvextend -l +100%FREE /dev/centos/root Size of logical volume centos/root changed from 50.06 GiB (12816 extents) to 325.76 GiB (83394 extents). Logical volume centos/root successfully resized.

4.扩展XFS文件空间大小

$ xfs_growfs /dev/mapper/centos-root meta-data=http://www.3lian.com/dev/mapper/centos-root isize=256 agcount=4, agsize=3276800 blks=sectsz=512 attr=2, projid32bit=1=crc=0 finobt=0 spinodes=0 data=bsize=4096 blocks=13107200, imaxpct=25=sunit=0 swidth=0 blks naming=version 2 bsize=4096 ascii-ci=0 ftype=0 log=internal bsize=4096 blocks=6400, version=2=sectsz=512 sunit=0 blks, lazy-count=1 realtime=none extsz=4096 blocks=0, rtextents=0 data blocks changed from 13107200 to 85395456