CentOS 6.2下删除逻辑卷和增加根目录空间

转自:http://kicklinux.com/lvm-manage-create-extend/

 

CentOS使用逻辑卷对磁盘空间进行管理，大大方便管理人员对空间的调整。很多童鞋安装系统时，分区使用默认设置，CentOS自动分配的home空间很大。因为我们生产环境中基本不使用home空间，所以决定把home挂载到lv_root逻辑卷上，把腾出的空间增加给lv_root逻辑卷。

查看系统目录的挂载情况：

[root@message1 /]# df -hFilesystem            Size  Used Avail Use% Mounted on/dev/mapper/vg_message1-lv_root                       50G  2.3G   45G   5% /tmpfs                1003M     0 1003M   0% /dev/shm/dev/cciss/c0d0p1     485M   32M  428M   7% /boot/dev/mapper/vg_message1-lv_home                       14G  163M   13G   2% /home[root@message1 /]# pvdisplay   --- Physical volume ---  PV Name               /dev/cciss/c0d0p2  VG Name               vg_message1  PV Size               67.84 GiB / not usable 4.00 MiB  Allocatable           yes (but full)  PE Size               4.00 MiB  Total PE              17367  Free PE               0  Allocated PE          17367  PV UUID               yKXnTp-6cWG-1MCG-FpHc-6QCX-nK1H-otKaMf[root@message1 /]# vgdisplay   --- Volume group ---  VG Name               vg_message1  System ID               Format                lvm2  Metadata Areas        1  Metadata Sequence No  4  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                3  Open LV               3  Max PV                0  Cur PV                1  Act PV                1  VG Size               67.84 GiB  PE Size               4.00 MiB  Total PE              17367  Alloc PE / Size       17367 / 67.84 GiB  Free  PE / Size       0 / 0     VG UUID               pDMn2R-tV0b-AL0Y-BRgV-focH-hpym-yoakDa[root@message1 /]# lvdisplay   --- Logical volume ---  LV Name                /dev/vg_message1/lv_root  VG Name                vg_message1  LV UUID                SAOoO3-Fwtk-wPYg-yi2X-6SXu-qgVZ-lVDz75  LV Write Access        read/write  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  --- Logical volume ---  LV Name                /dev/vg_message1/lv_home  VG Name                vg_message1  LV UUID                xcjRkh-gSR3-ykfu-LRtV-RA47-3c7q-ZsqqBf  LV Write Access        read/write  LV Status              available  # open                 1  LV Size                13.90 GiB  Current LE             3559  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     256  Block device           253:2  --- Logical volume ---  LV Name                /dev/vg_message1/lv_swap  VG Name                vg_message1  LV UUID                bJcLZE-uG1l-KNpU-OgNH-VceH-ib4d-gGOuKO  LV Write Access        read/write  LV Status              available  # open                 1  LV Size                3.94 GiB  Current LE             1008  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     256  Block device           253:1

确认home目录下没有数据后，将home目录卸载，这时home目录将使用lv_root逻辑卷进行存储。

[root@message1 /]# umount /home[root@message1 /]# df -hFilesystem            Size  Used Avail Use% Mounted on/dev/mapper/vg_message1-lv_root                       50G  2.3G   45G   5% /tmpfs                1003M     0 1003M   0% /dev/shm/dev/cciss/c0d0p1     485M   32M  428M   7% /boot

这时就可以删除lv_home

[root@message1 /]# lvremove /dev/vg_message1/lv_homeDo you really want to remove active logical volume lv_home? [y/n]: y  Logical volume "lv_home" successfully removed

查看逻辑卷信息，发现lv_home已经删除

[root@message1 /]# lvdisplay   --- Logical volume ---  LV Name                /dev/vg_message1/lv_root  VG Name                vg_message1  LV UUID                SAOoO3-Fwtk-wPYg-yi2X-6SXu-qgVZ-lVDz75  LV Write Access        read/write  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  --- Logical volume ---  LV Name                /dev/vg_message1/lv_swap  VG Name                vg_message1  LV UUID                bJcLZE-uG1l-KNpU-OgNH-VceH-ib4d-gGOuKO  LV Write Access        read/write  LV Status              available  # open                 1  LV Size                3.94 GiB  Current LE             1008  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     256  Block device           253:1

发现逻辑卷组已经有13.9G的空间空闲

[root@message1 /]# vgdisplay   --- Volume group ---  VG Name               vg_message1  System ID               Format                lvm2  Metadata Areas        1  Metadata Sequence No  5  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                2  Open LV               2  Max PV                0  Cur PV                1  Act PV                1  VG Size               67.84 GiB  PE Size               4.00 MiB  Total PE              17367  Alloc PE / Size       13808 / 53.94 GiB  Free  PE / Size       3559 / 13.90 GiB  VG UUID               pDMn2R-tV0b-AL0Y-BRgV-focH-hpym-yoakDa

将所有空闲空间增加给逻辑卷lv_root

[root@message1 ~]# lvextend -L +13.9G /dev/vg_message1/lv_root  Rounding up size to full physical extent 13.90 GiB  Extending logical volume lv_root to 63.90 GiB  Logical volume lv_root successfully resized

查看当前系统逻辑卷信息，发现lv_root的空间大小发生变化

[root@message1 ~]# lvdisplay   --- Logical volume ---  LV Name                /dev/vg_message1/lv_root  VG Name                vg_message1  LV UUID                SAOoO3-Fwtk-wPYg-yi2X-6SXu-qgVZ-lVDz75  LV Write Access        read/write  LV Status              available  # open                 1  LV Size                63.90 GiB  Current LE             16359  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     256  Block device           253:0  --- Logical volume ---  LV Name                /dev/vg_message1/lv_swap  VG Name                vg_message1  LV UUID                bJcLZE-uG1l-KNpU-OgNH-VceH-ib4d-gGOuKO  LV Write Access        read/write  LV Status              available  # open                 1  LV Size                3.94 GiB  Current LE             1008  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     256  Block device           253:1

此时查看文件系统的根目录空间并没有发生变化

[root@message1 ~]# df -hFilesystem            Size  Used Avail Use% Mounted on/dev/mapper/vg_message1-lv_root                       50G  2.3G   45G   5% /tmpfs                1003M     0 1003M   0% /dev/shm/dev/cciss/c0d0p1     485M   32M  428M   7% /boot

调整文件系统空间

[root@message1 ~]# resize2fs -p /dev/vg_message1/lv_root resize2fs 1.41.12 (17-May-2010)Filesystem at /dev/vg_message1/lv_root is mounted on /; on-line resizing requiredold desc_blocks = 4, new_desc_blocks = 4Performing an on-line resize of /dev/vg_message1/lv_root to 16751616 (4k) blocks.The filesystem on /dev/vg_message1/lv_root is now 16751616 blocks long.

查看文件系统空间大小，发现根目录由50G增加到63G，到此文件系统空间调整完成。

[root@message1 ~]# df -hFilesystem            Size  Used Avail Use% Mounted on/dev/mapper/vg_message1-lv_root                       63G  2.3G   58G   4% /tmpfs                1003M     0 1003M   0% /dev/shm/dev/cciss/c0d0p1     485M   32M  428M   7% /boot

修改操作系统挂载目录的配置文件/etc/fstab，注释掉home挂载,注意一定要操作这一步哦，不然下次重启系统就无法启动啦。

[root@message1 ~]# more /etc/fstab ## /etc/fstab# Created by anaconda on Tue Jul 10 19:51:36 2012## Accessible filesystems, by reference, are maintained under '/dev/disk'# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info#/dev/mapper/vg_message1-lv_root /                       ext4    defaults        1 1UUID=cfe0f4a9-5a71-4089-8258-e1c0105de411 /boot                   ext4    defaults        1 2#/dev/mapper/vg_message1-lv_home /home                   ext4    defaults        1 2/dev/mapper/vg_message1-lv_swap swap                    swap    defaults        0 0tmpfs                   /dev/shm                tmpfs   defaults        0 0devpts                  /dev/pts                devpts  gid=5,mode=620  0 0sysfs                   /sys                    sysfs   defaults        0 0proc                    /proc                   proc    defaults        0 0

看了以后是不是觉得逻辑卷管理简单而且方便啊！