Accommodate growth of a VM by expanding an LVM partition
At some point, a “physical volume” may have to be enlarged to accommodate growth on a VM. This is how you grow the filesystem of an existing VMDK without adding an additional disk to your VM.
Enlarging a VMDK
- login to VMware
- Find the VM with the disk that needs to be made larger
- Right click and select “Edit Settings”
- Find the specific Hard Disk and update the capacity to the desired size
- Click “Ok”
Expanding the VM Volume Size
In most cases, the “Physical Volume” information will not be updated automatically. To force a recheck of the SCSI bus and drive settings run the following commands.
Figure out the configured SCSI ID
[root@server ~]# cat /proc/scsi/scsi
Attached devices:
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: NECVMWar Model: VMware IDE CDR10 Rev: 1.00
Type: CD-ROM ANSI SCSI revision: 05
Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: VMware Model: Virtual disk Rev: 1.0
Type: Direct-Access ANSI SCSI revision: 02
Using output from the above sample the command would be
echo '1' > /sys/class/scsi_disk/2\:0\:0\:0/device/rescan
Use fdisk to Edit the Drive Geometry
The below is an example and may be different on the actual host you are enlarging a partition on. Do not proceed unless you know what you are doing.
fdisk /dev/sda
Hit p to print configuration
WARNING: DOS-compatible mode is deprecated. It is strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): p
Disk /dev/sda: 375.8 GB, 375809638400 bytes
255 heads, 63 sectors/track, 45689 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: 0x00048792
Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 32635 261627613+ 8e Linux LVM
Hit d and then enter the partition number. In the above example there are only two partitions so 2 is the appropriate number
Command (m for help): d Partition number (1-4): 2
Make sure not to change the starting cylinder to anything other than its original value. Doing so may result in data loss.
Hit n to create a new partition
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (64-45689, default 64):
Using default value 64
Last cylinder, +cylinders or +size{K,M,G} (64-45689, default 45689):
Using default value 45689
Hit t to change the partition type to LVM (8e)
Command (m for help): t Partition number (1-4): 2 Hex code (type L to list codes): 8e Changed system type of partition 2 to 8e (Linux LVM)
Hit p to verify the new partition table is correct and hit w to write changes
Command (m for help): p Disk /dev/sda: 375.8 GB, 375809638400 bytes 255 heads, 63 sectors/track, 45689 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: 0x00048792 Device Boot Start End Blocks Id System /dev/sda1 * 1 64 512000 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 64 45689 366483868+ 8e Linux LVM Command (m for help): w The partition table has been altered!
If making changes to the disk where the root / partition is mounted, the system will have to be restarted
shutdown -r now
Resize the Physical Volume
Resize physical volume
pvresize /dev/sda2 pvscan
Extend the logical volume you wanted to grow
lvextend -L +100G /dev/vg_local/lv_var
Depending on the partition type xfs or ext4, pick the instructions that are most appropriate. You can check by using df -Tf or lsblk -f
a:) Resize ext4 Partition
resize2fs /dev/vg_local/lv_var
b:) Resize xfs Partition
yum install xfsprogs.x86_64 xfs_growfs /dev/vg_local/lv_var
Check Volume Size
lvdisplay
