Linux中的LVM增加容量与删除卷的方法介绍

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放大LV容量涉及到LVM管理中的命令lvresize，我们先创建一个卷组VG VolGroup02，它建立在磁盘/dev/sdc （大小为8G）上。创建逻辑卷LV时，我们故意只使用了一小部分。具体情况如下所示

代码如下:

[root@localhost ~]# vgdisplay
 --- Volume group ---
 VG Name               VolGroup02
 System ID            
 FORMat                lvm2
 Metadata Areas        1
 Metadata Sequence No  1
 VG Access             read/write
 VG Status             resizable
 MAX LV                0
 Cur LV                0
 Open LV               0
 Max PV                0
 Cur PV                1
 Act PV                1
 VG Size               7.97 GiB
 PE Size               32.00 MiB
 Total PE              255
 Alloc PE / Size       0 / 0  
 Free  PE / Size       255 / 7.97 GiB
 VG UUID               SETgjx-dobd-Uayt-AWgN-HKID-hsYe-tEotIS
[root@localhost ~]# lvcreate -L7.97 -n LogVol00 VolGroup02
 Rounding up size to full physical extent 32.00 MiB
 Logical volume "LogVol00" created
[root@localhost ~]# mkfs -t ext4 /dev/VolGroup02/LogVol00
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
8192 inodes, 32768 blocks
1638 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=33554432
4 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
       8193, 24577

Writing inode tables: done                            
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
[root@localhost ~]# cd /
[root@localhost /]# mkdir /u01
[root@localhost /]# mount /dev/VolGroup02/LogVol00 /u01
[root@localhost /]# vi /etc/fstab

#
# /etc/fstab
# Created by anaconda on Mon Aug 17 15:08:21 2015
#
# 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
#
UUID=3440ad55-6486-45ed-876f-e942b08013bf /                       ext4    defaults        1 1
UUID=d3abb655-db70-4c42-967d-57c421abfda0 /boot                   ext4    defaults        1 2
UUID=660624ff-335d-42ca-b779-f130a80d9da8 /home                   ext4    defaults        1 2
UUID=6f534bf0-e486-4937-84ae-ed1221cf34f1 swap                    swap    defaults        0 0
/dev/VolGroup02/LogVol00                  /u01                    ext4    defaults        1 1
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0

此时，我们要放大文件系统/u01的大小，那么就需要使用到lvresize 放大LV容量

代码如下:

[root@localhost ~]# lvscan
 ACTIVE            '/dev/VolGroup02/LogVol00' [32.00 MiB] inherit
[root@localhost ~]# lvdisplay /dev/VolGroup02/LogVol00
 --- Logical volume ---
 LV Path                /dev/VolGroup02/LogVol00
 LV Name                LogVol00
 VG Name                VolGroup02
 LV UUID                OCHwx1-EL9P-6C5J-RNuz-2Xu5-4215-H3xt5s
 LV Write Access        read/write
 LV Creation host, time localhost.localdomain, 2015-09-01 10:50:10 +0800
 LV Status              available
 # open                 1
 LV Size                32.00 MiB
 Current LE             1
 Segments               1
 Allocation             inherit
 Read ahead sectors     auto
 - currently set to     256
 Block device           253:0
 
[root@localhost ~]# lvresize -L +7.89G /dev/VolGroup02/LogVol00
 Rounding size to boundary between physical extents: 7.91 GiB
 Size of logical volume VolGroup02/LogVol00 changed from 32.00 MiB (1 extents) to 7.94 GiB (254 extents).
 Logical volume LogVol00 successfully resized

代码如下:

[root@localhost ~]# resize2fs -p /dev/VolGroup02/LogVol00
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/VolGroup02/LogVol00 is mounted on /u01; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 32
Performing an on-line resize of /dev/VolGroup02/LogVol00 to 8323072 (1k) blocks.
The filesystem on /dev/VolGroup02/LogVol00 is now 8323072 blocks long.

[root@localhost ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              27G  6.0G   20G  24% /
tmpfs                 5.9G     0  5.9G   0% /dev/shm
/dev/sda1             477M   32M  420M   8% /boot
/dev/sdb1              99G   60M   94G   1% /home
/dev/mapper/VolGroup02-LogVol00
                     7.7G  2.7M  7.3G   1% /u01

如果我们此时在虚拟机上将磁盘从8G扩展为10G，那么要如何利用扩展的磁盘空间呢？

代码如下:

[root@localhost u01]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes
64 heads, 32 sectors/track, 40960 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000462cf

  Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           2         501      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2             502       28672    28847104   83  Linux
Partition 2 does not end on cylinder boundary.
/dev/sda3           28673       40960    12582912   82  Linux swap / Solaris
Partition 3 does not end on cylinder boundary.

Disk /dev/sdc: 8589 MB, 8589934592 bytes
64 heads, 32 sectors/track, 8192 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x98c391fe

  Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1        8192     8388592   83  Linux

Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0002488e

  Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       13055   104856576   83  Linux

Disk /dev/mapper/VolGroup02-LogVol00: 33 MB, 33554432 bytes
255 heads, 63 sectors/track, 4 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

重启过后才能看到/dev/sdc的空间变化情况。


删除物理卷
删除卷LVM管理中的命令vgreduce, pvremove：

   vgreduce：通过删除LVM卷组中的物理卷来减少卷组容量。注意：不能删除LVM卷组中剩余的最后一个物理卷

   pvremove: 用于删除一个存在的物理卷。使用pvremove指令删除物理卷时，它将LVM分区上的物理卷信息删除，使其不再被视为一个物理卷。

在删除物理卷PV之前，必须将服务器的分区信息、卷组信息、物理卷信息、逻辑卷信息都掌握清楚，避免出现失误或误操作。

代码如下:

[root@localhost ~]# fdisk -l

Disk /dev/sda: 128.8 GB, 128849018880 bytes
255 heads, 63 sectors/track, 15665 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

  Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14       10443    83778975   8e  Linux LVM
/dev/sda3           10444       15665    41945715   83  Linux
[root@localhost ~]# vgscan
 Reading all physical volumes.  This may take a while...
 Found volume group "VolGroup00" using metadata type lvm2
[root@localhost ~]# pvscan
 PV /dev/sda2   VG VolGroup00   lvm2 [79.88 GB / 0    free]
 PV /dev/sda3   VG VolGroup00   lvm2 [40.00 GB / 40.00 GB free]
 Total: 2 [119.88 GB] / in use: 2 [119.88 GB] / in no VG: 0 [0   ]
[root@localhost ~]# pvdisplay
 --- Physical volume ---
 PV Name               /dev/sda2
 VG Name               VolGroup00
 PV Size               79.90 GB / not usable 23.41 MB
 Allocatable           yes (but full)
 PE Size (KByte)       32768
 Total PE              2556
 Free PE               0
 Allocated PE          2556
 PV UUID               YGtB2J-ZKJr-mV62-NluQ-2DGy-vuUT-cCc1lo
 
 --- Physical volume ---
 PV Name               /dev/sda3
 VG Name               VolGroup00
 PV Size               40.00 GB / not usable 2.61 MB
 Allocatable           yes
 PE Size (KByte)       32768
 Total PE              1280
 Free PE               1280
 Allocated PE          0
 PV UUID               wsnv13-7j1H-SH8q-hl6k-HpNc-x4WU-gM7LzW
 
[root@localhost ~]# lvscan
 ACTIVE            '/dev/VolGroup00/LogVol00' [77.91 GB] inherit
 ACTIVE            '/dev/VolGroup00/LogVol01' [1.97 GB] inherit
[root@localhost ~]# lvs
 LV       VG         Attr   LSize  Origin Snap%  Move Log Copy%  Convert
 LogVol00 VolGroup00 -wi-ao 77.91G                                      
 LogVol01 VolGroup00 -wi-ao  1.97G    

vgreduce参数：
-a：如果命令行中没有指定要删除的物理卷，则删除所有的空物理卷；

--removemissing：删除卷组中丢失的物理卷，使卷组恢复正常状态。

代码如下:

[root@localhost ~]# vgreduce VolGroup00 /dev/sda3
Removed "/dev/sda3" from volume group "VolGroup00"
[root@localhost ~]#

代码如下:

[root@localhost ~]# pvscan
 PV /dev/sda2   VG VolGroup00      lvm2 [79.88 GB / 0    free]
 PV /dev/sda3                      lvm2 [40.00 GB]
 Total: 2 [119.88 GB] / in use: 1 [79.88 GB] / in no VG: 1 [40.00 GB]
[root@localhost ~]# pvs
 PV         VG         Fmt  Attr PSize  PFree
 /dev/sda2  VolGroup00 lvm2 a-   79.88G     0
 /dev/sda3             lvm2 a-   40.00G 40.00G
[root@localhost ~]# pvremove /dev/sda3
 Labels on physical volume "/dev/sda3" successfully wiped
[root@localhost ~]# pvscan
 PV /dev/sda2   VG VolGroup00   lvm2 [79.88 GB / 0    free]
 Total: 1 [79.88 GB] / in use: 1 [79.88 GB] / in no VG: 0 [0   ]

感谢各位的阅读，以上就是“Linux中的LVM增加容量与删除卷的方法介绍”的内容了，经过本文的学习后，相信大家对Linux中的LVM增加容量与删除卷的方法介绍这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！