Cluster 24. Resizing LVM image of the Virtual Machine.

On guest:
fdisk -l /dev/vda

Resize LV to be 20GB:
lvresize -L 21474836480b /dev/agrp-c01n02_vg0/vm-test
  Size of logical volume agrp-c01n02_vg0/vm-test changed from 15.00 GiB (3840 extents) to 20.00 GiB (5120 extents).
  Logical volume agrp-c01n02_vg0/vm-test successfully resized.

Find domain ID:
virsh list
 Id    Name                           State
----------------------------------------------------
 1     vm-test                 running

Resize vda of the guest:

virsh blockresize  --path /dev/agrp-c01n02_vg0/vm-test --size 21474836480b  1

Block device '/dev/agrp-c01n02_vg0/vm-test' is resized

On guest - check that vda is resized to the needed size:

lsblk -a | grep ^vda 

vda                         252:0    0   20G  0 disk 

View last partition index (here it's 2 because of vda2) on the guest:

lsblk -a | grep vda

vda                         252:0    0   20G  0 disk 

├─vda1                      252:1    0  500M  0 part /boot

└─vda2                      252:2    0 14.5G  0 part 

Find end of the last partition (text in bold is end - 31208) on the guest:

fdisk -l

Disk /dev/vda: 21.5 GB, 21474836480 bytes

16 heads, 63 sectors/track, 41610 cylinders

Units = cylinders of 1008 * 512 = 516096 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x000a4595

   Device Boot      Start         End      Blocks   Id  System

/dev/vda1   *           3        1018      512000   83  Linux

Partition 1 does not end on cylinder boundary.

/dev/vda2            1018       31208    15215616   8e  Linux LVM

Create new partition vda3 on the guest:

fdisk /dev/vda 

input n letter # for creating new partition

input p # for primary partition 

input 3 # for new partition index

input 31208 # for "First cylinder (1-41610, default 1):"

enter # to accept "Last cylinder, +cylinders or +size{K,M,G} (31208-41610, default 41610):"

input w # to save 

View current partition table on the guest:

partx -l /dev/vda

Re-read partition table:

partx -a /dev/vda # this will give "BLKPG: Device or resource busy" for already added partition

Check that we have device nodes for /dev/sdb itself and the partitions on it:

ls /dev/vda*

/dev/vda  /dev/vda1  /dev/vda2 /dev/vda3

Create PV and verify on the guest:

pvcreate /dev/vda3

  Physical volume "/dev/vda3" successfully created

pvs

 PV         VG       Fmt  Attr PSize  PFree

  /dev/vda2  VolGroup lvm2 a--  14.51g    0 

  /dev/vda3           lvm2 ---   5.00g 5.00g

Extend VG with new PV nad verify:

vgextend VolGroup /dev/vda3

  Volume group "VolGroup" successfully extended

pvs

  PV         VG       Fmt  Attr PSize  PFree

  /dev/vda2  VolGroup lvm2 a--  14.51g    0 

  /dev/vda3  VolGroup lvm2 a--   5.00g 5.00g

Extend LV size to the all available free space on the guest:

lvextend -l +100%FREE /dev/VolGroup/lv_root 

  Size of logical volume VolGroup/lv_root changed from 13.01 GiB (3330 extents) to 18.00 GiB (4609 extents).

  Logical volume lv_root successfully resized

Verify on the guest:

lvs

  LV      VG       Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert

  lv_root VolGroup -wi-ao---- 18.00g                                                    

  lv_swap VolGroup -wi-ao----  1.50g 

Resize file system on the guest:
For ext type filesystem:

resize2fs /dev/VolGroup/lv_root

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/VolGroup/lv_root is mounted on /; on-line resizing required

old desc_blocks = 1, new_desc_blocks = 2

Performing an on-line resize of /dev/VolGroup/lv_root to 4719616 (4k) blocks.

The filesystem on /dev/VolGroup/lv_root is now 4719616 blocks long.
For xfs filesystem:
xfs_growfs /dev/VolGroup/lv_root

Verify on guest:

df -h

Filesystem                                   Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root      18G  9.3G  7.5G  56% /

tmpfs                                           939M     0  939M   0% /dev/shm

/dev/vda1                                    477M   48M  405M  11% /boot