3) 将上面查到的空闲空间中的90G增减到/home分区上
| [root@localhost ~]# lvextend -L +90G /dev/mapper/centos-home //或者使用－l参数（跟PE数量），即lvextend -l +25500 /dev/mapper/centos-home Size of logical volume centos/home changed from 628.00 GiB (160768 extents) to 718.00 GiB (183808 extents). Logical volume centos/home successfully resized. [root@localhost ~]# xfs_growfs /dev/mapper/centos-home meta-data=/dev/mapper/centos-home isize=512 agcount=4, agsize=41156608 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=0 spinodes=0 data = bsize=4096 blocks=164626432, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=1 log =internal bsize=4096 blocks=80384, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 data blocks changed from 164626432 to 188219392 |
4）再次看着系统分区，发现home分区已经增加了90G（这种方式增加后，home分区之前的数据还不会丢失）
| [root@localhost ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/mapper/centos-root 200G 2.2G 198G 2% / devtmpfs 32G 0 32G 0% /dev tmpfs 32G 0 32G 0% /dev/shm tmpfs 32G 49M 32G 1% /run tmpfs 32G 0 32G 0% /sys/fs/cgroup /dev/sda1 197M 139M 59M 71% /boot tmpfs 6.3G 0 6.3G 0% /run/user/0 /dev/mapper/centos-home 718G 33M 718G 1% /home |
虽然xfs文件系统只支持增加，不支持减少。但并不是说在xfs系统文件下不能减小，只是减小后，需要重新格式化才能挂载上。这样原来的数据就丢失了！
实例2: 这种情况只适用于系统刚安装好，逻辑分区内没有什么数据或数据不多且不重要可以删除或拷贝的情况下
系统安装好后，发现home分区过大，想从home分区中拿出100G给／分区
| [root@localhost ~]# df -hT 文件系统 类型 容量 已用 可用 已用% 挂载点 /dev/mapper/centos-root xfs 205G 2.2G 203G 2% / devtmpfs devtmpfs 32G 0 32G 0% /dev tmpfs tmpfs 32G 0 32G 0% /dev/shm tmpfs tmpfs 32G 49M 32G 1% /run tmpfs tmpfs 32G 0 32G 0% /sys/fs/cgroup /dev/sda1 xfs 197M 139M 59M 71% /boot tmpfs tmpfs 6.3G 0 6.3G 0% /run/user/0 /dev/mapper/centos-home xfs 718G 33M 718G 1% /home [root@localhost ~]# umount /home/ [root@localhost ~]# lvreduce -L -100G /dev/mapper/centos-home WARNING: Reducing active logical volume to 618.00 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 718.00 GiB (183808 extents) to 618.00 GiB (158208 extents). Logical volume centos/home successfully resized. |
如下，很显然xfs文件系统不能执行分区减小的调整！
| [root@localhost ~]# xfs_growfs /dev/mapper/centos-home xfs_growfs: /dev/mapper/centos-home is not a mounted XFS filesystem [root@localhost ~]# mount /dev/mapper/centos-home /home/ mount: /dev/mapper/centos-home：不能读超级块 |
