Redhat Linux5.3 32bit操作系统LVM学习笔记之二（在线调整镜像卷大小）



本文以Linux5.4 32Bit操作系统为例，简要说明LVM的管理操作。
此操作系统版本旧，LVM功能相对于rhel6和rhel7有很多不足之处，可用参数也不够多。

以下操作是在vmware虚拟机中测试。

在生产中建议尽快升级操作系统，或迁移应用到更高的操作系统版本上。

1、在线缩小，无法在线完成，需要umount文件系统才能做缩小,,风险较大，建议备份数据后再操作
[root@linux54 ~]# resize2fs /dev/datavg/datalv01  4g
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/datavg/datalv01 is mounted on /data; on-line resizing required
On-line shrinking from 1572864 to 1048576 not supported.

[root@linux54 ~]# umount /data

[root@linux54 ~]# resize2fs /dev/datavg/datalv01  4g
resize2fs 1.39 (29-May-2006)
Please run 'e2fsck -f /dev/datavg/datalv01' first.

[root@linux54 ~]# e2fsck -f /dev/datavg/datalv01
e2fsck 1.39 (29-May-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/datavg/datalv01: 11/786432 files (9.1% non-contiguous), 60560/1572864 blocks
[root@linux54 ~]# resize2fs /dev/datavg/datalv01  4g
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/datavg/datalv01 to 1048576 (4k) blocks.
The filesystem on /dev/datavg/datalv01 is now 1048576 blocks long.

[root@linux54 ~]# lvreduce -L 4G /dev/datavg/datalv01
  WARNING: Reducing active logical volume to 4.00 GB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce datalv01? [y/n]: y
  Reducing logical volume datalv01 to 4.00 GB
  Logical volume datalv01 successfully resized
[root@linux54 ~]#
[root@linux54 ~]# mount  /dev/datavg/datalv01  /data
[root@linux54 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/rootvg-root
                       17G  2.6G   14G  16% /
/dev/sda1             487M   17M  445M   4% /boot
tmpfs                1014M     0 1014M   0% /dev/shm
/dev/mapper/datavg-datalv01
                      4.0G  141M  3.7G   4% /data
[root@linux54 ~]# lvs -a -o +devices |grep datalv01
  datalv01            datavg mwi-ao  4.00G                        100.00         datalv01_mimage_0(0),datalv01_mimage_1(0)
  [datalv01_mimage_0] datavg iwi-ao  4.00G                                       /dev/sdb(0)                             
  [datalv01_mimage_1] datavg iwi-ao  4.00G                                       /dev/sdc(0)                             
[root@linux54 ~]# pvs --segment -v |grep datalv01
    Scanning for physical volume names
  /dev/sdb   datavg lvm2 a-    5.00G 1020.00M     0  1024 [datalv01_mimage_0]     0 linear /dev/sdb:0-1023 
  /dev/sdc   datavg lvm2 a-    5.00G 1020.00M     0  1024 [datalv01_mimage_1]     0 linear /dev/sdc:0-1023 
[root@linux54 ~]#

2、在线扩大，占满所在磁盘空间
[root@linux54 ~]# lvextend -l 1279 /dev/datavg/datalv01
  Extending 2 mirror images.
  Extending logical volume datalv01 to 5.00 GB
  Logical volume datalv01 successfully resized
[root@linux54 ~]#
[root@linux54 ~]# resize2fs  /dev/datavg/datalv01   不加大小，就是调整到lv大小
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/datavg/datalv01 is mounted on /data; on-line resizing required
Performing an on-line resize of /dev/datavg/datalv01 to 1309696 (4k) blocks.
The filesystem on /dev/datavg/datalv01 is now 1309696 blocks long.
[root@linux54 ~]#
[root@linux54 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/rootvg-root
                       17G  2.6G   14G  16% /
/dev/sda1             487M   17M  445M   4% /boot
tmpfs                1014M     0 1014M   0% /dev/shm
/dev/mapper/datavg-datalv01
                      5.0G  141M  4.7G   3% /data
[root@linux54 ~]# 
[root@linux54 ~]# lvs -a -o +devices |grep datalv01
  datalv01            datavg mwi-ao  5.00G                        100.00         datalv01_mimage_0(0),datalv01_mimage_1(0)
  [datalv01_mimage_0] datavg iwi-ao  5.00G                                       /dev/sdb(0)                             
  [datalv01_mimage_1] datavg iwi-ao  5.00G                                       /dev/sdc(0)                             
[root@linux54 ~]# pvs --segment -v
    Scanning for physical volume names
  PV         VG     Fmt  Attr PSize  PFree Start SSize LV                  Start Type   PE Ranges       
  /dev/sda2  rootvg lvm2 a-   19.50G    0      0   560 root                    0 linear /dev/sda2:0-559 
  /dev/sda2  rootvg lvm2 a-   19.50G    0    560    64 swap                    0 linear /dev/sda2:560-623
  /dev/sdb   datavg lvm2 a-    5.00G    0      0  1279 [datalv01_mimage_0]     0 linear /dev/sdb:0-1278 
  /dev/sdc   datavg lvm2 a-    5.00G    0      0  1279 [datalv01_mimage_1]     0 linear /dev/sdc:0-1278 
  /dev/sdd   datavg lvm2 a-    5.00G 5.00G     0  1279                         0 free                   
  /dev/sde   datavg lvm2 a-    5.00G 5.00G     0  1279                         0 free                   
[root@linux54 ~]#

3、在线扩大

[root@linux54 ~]# lvextend -L 8g /dev/datavg/datalv01  /dev/sdd /dev/sde   可以不指定磁盘，在卷组中的磁盘扩大。某些场合需要指定。例如镜像的存储来源不同。
  Extending 2 mirror images.
  Extending logical volume datalv01 to 8.00 GB
  Logical volume datalv01 successfully resized
[root@linux54 ~]#
[root@linux54 ~]# resize2fs /dev/datavg/datalv01  8g             这个操作无发放置到后台运行，如果扩展的空间较大，花费的时间相当长。算是这个版本LVM的一个重大弱点。
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/datavg/datalv01 is mounted on /data; on-line resizing required
Performing an on-line resize of /dev/datavg/datalv01 to 2097152 (4k) blocks.
The filesystem on /dev/datavg/datalv01 is now 2097152 blocks long.
[root@linux54 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/rootvg-root
                       17G  2.6G   14G  16% /
/dev/sda1             487M   17M  445M   4% /boot
tmpfs                1014M     0 1014M   0% /dev/shm
/dev/mapper/datavg-datalv01
                      7.9G  142M  7.6G   2% /data
[root@linux54 ~]#
[root@linux54 ~]# pvs --segment -v |grep datalv01
    Scanning for physical volume names
  /dev/sdb   datavg lvm2 a-    5.00G    0      0  1279 [datalv01_mimage_0]     0 linear /dev/sdb:0-1278 
  /dev/sdc   datavg lvm2 a-    5.00G    0      0  1279 [datalv01_mimage_1]     0 linear /dev/sdc:0-1278 
  /dev/sdd   datavg lvm2 a-    5.00G 1.99G     0   769 [datalv01_mimage_0]  1279 linear /dev/sdd:0-768  
  /dev/sde   datavg lvm2 a-    5.00G 1.99G     0   769 [datalv01_mimage_1]  1279 linear /dev/sde:0-768  
[root@linux54 ~]# lvs -a -o +devices |grep datalv01
  datalv01            datavg mwi-ao  8.00G                        100.00         datalv01_mimage_0(0),datalv01_mimage_1(0)
  [datalv01_mimage_0] datavg iwi-ao  8.00G                                       /dev/sdb(0)                             
  [datalv01_mimage_0] datavg iwi-ao  8.00G                                       /dev/sdd(0)                             
  [datalv01_mimage_1] datavg iwi-ao  8.00G                                       /dev/sdc(0)                             
  [datalv01_mimage_1] datavg iwi-ao  8.00G                                       /dev/sde(0)                             
[root@linux54 ~]#