linux如何无损调整分区大小

情况：

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 -hFilesystem        Size Used Avail Use% Mounted on/dev/mapper/centos-root  50G  50G  19M 100% /devtmpfs         32G   0  32G  0% /devtmpfs           32G   0  32G  0% /dev/shmtmpfs           32G 2.5G  29G  8% /runtmpfs           32G   0  32G  0% /sys/fs/cgroup/dev/mapper/centos-home 476G  33M 476G  1% /home/dev/sda1        497M 238M 259M 48% /boottmpfs          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/homeLV Name        homeVG Name        centosLV UUID        1fAt1E-bQsa-1HXR-MCE2-5VZ1-xzBz-iI1SLvLV Write Access    read/writeLV Creation host, time localhost, 2016-10-26 17:23:47 +0800LV Status       available# open         0LV Size        475.70 GiBCurrent LE       121778Segments        1Allocation       inheritRead ahead sectors   auto- currently set to   256Block device      253:2--- Logical volume ---LV Path        /dev/centos/rootLV Name        rootVG Name        centosLV UUID        lD64zY-yc3Z-SZaB-dAjK-03YM-2gM8-pfj4ooLV Write Access    read/writeLV Creation host, time localhost, 2016-10-26 17:23:48 +0800LV Status       available# open         1LV Size        50.00 GiBCurrent LE       12800Segments        1Allocation       inheritRead ahead sectors   auto- currently set to   256Block 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/homeWARNING: 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/rootSize 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-rootmeta-data=/dev/mapper/centos-root isize=256  agcount=4, agsize=3276800 blks     =            sectsz=512  attr=2, projid32bit=1     =            crc=0    finobt=0 spinodes=0data   =            bsize=4096  blocks=13107200, imaxpct=25     =            sunit=0   swidth=0 blksnaming  =version 2       bsize=4096  ascii-ci=0 ftype=0log   =internal        bsize=4096  blocks=6400, version=2     =            sectsz=512  sunit=0 blks, lazy-count=1realtime =none          extsz=4096  blocks=0, rtextents=0data blocks changed from 13107200 to 85395456