HOW TO REDUCE THE SIZE OF VG(VOLUME GROUP) IN LINUX

In this article we will learn how to reduce size of volume group .

volume group in linux

Follow these steps :

  • Create four partitions 
[root@localhost ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 6147.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (5482-6147, default 5482):
Using default value 5482
Last cylinder or +size or +sizeM or +sizeK (5482-6147, default 6147): +500M

Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (5544-6147, default 5544):
Using default value 5544
Last cylinder or +size or +sizeM or +sizeK (5544-6147, default 6147): +500M
Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (5606-6147, default 5606):
Using default value 5606
Last cylinder or +size or +sizeM or +sizeK (5606-6147, default 6147): +500M

Command (m for help): n
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (5668-6147, default 5668):
Using default value 5668
Last cylinder or +size or +sizeM or +sizeK (5668-6147, default 6147): +500M

Command (m for help): p
Disk /dev/sda: 50.5 GB, 50562793472 bytes
255 heads, 63 sectors/track, 6147 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        5099    40957686   83  Linux
/dev/sda2            5100        5481     3068415   82  Linux swap / Solaris
/dev/sda4            5482        6147     5349645    5  Extended
/dev/sda5            5482        5543      497983+  83  Linux
/dev/sda6            5544        5605      497983+  83  Linux
/dev/sda7            5606        5667      497983+  83  Linux
/dev/sda8            5668        5729      497983+  83  Linux

Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
[root@localhost ~]# partprobe /dev/sda
  • Now create pv (physical volume) including sda5 ,sda6, sda7, sda8
[root@localhost ~]# pvcreate /dev/sda5 /dev/sda6 /dev/sda7 /dev/sda8
  Physical volume "/dev/sda5" successfully created
  Physical volume "/dev/sda6" successfully created
  Physical volume "/dev/sda7" successfully created
  Physical volume "/dev/sda8" successfully created
  • Create volume group including those pv(physical volumes)
[root@localhost ~]# vgcreate vg00 /dev/sda5 /dev/sda6 /dev/sda7 /dev/sda8
  Volume group "vg00" successfully created
  • You can check the the size of vg(volume group)
[root@localhost ~]# vgs
  VG   #PV #LV #SN Attr   VSize VFree
  vg00   4   0   0 wz--n- 1.89G 1.89G
  • Now we are going to remove one partition to reduce the size of vg (volume group)
[root@localhost ~]# vgreduce vg00 /dev/sda8
  Removed "/dev/sda8" from volume group "vg00"
  • You can check the size its now been reduced .
[root@localhost ~]# vgs
  VG   #PV #LV #SN Attr   VSize VFree
  vg00   3   0   0 wz--n- 1.42G 1.42G

So this is how you can reduce the size of vg (volume group)

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