Extend the KVM disk image. This time, we will expand the disk on a machine using LVM. Expand to 20GB from + 10GB to 10GB.
The virtual machine disk looks like this.
# df -h
File system size used Remaining used%Mount position
/dev/mapper/centos-root 8.5G 6.5G 2.1G 76% /
devtmpfs 485M 0 485M 0% /dev
tmpfs 496M 0 496M 0% /dev/shm
tmpfs 496M 7.1M 489M 2% /run
tmpfs 496M 0 496M 0% /sys/fs/cgroup
/dev/vdb 2.6T 1.6T 1016G 62% /storage
/dev/vda1 497M 217M 280M 44% /boot
tmpfs 100M 0 100M 0% /run/user/1000
First, extend the disk image file on the virtual host. Make a backup of the image.
# cp -a /var/lib/libvirt/images/water1.img{,.bak}
Confirmation of current image
# qemu-img info water01.img
image: water01.img
file format: raw
virtual size: 10G (10737418240 bytes)
disk size: 10G
Add 10GB to a 10GB image
# qemu-img resize water01.img +10G
Image resized.
Start the machine here and operate on the virtual machine thereafter. Edit disk with fdisk
# fdisk /dev/vda
command(Help with m): p #Confirmation (confirm that it is a sector unit at the same time)
disk/dev/vda: 128.8 GB,128849018880 bytes
Head 16,Sector 63,Cylinder 249660,Total 251658240 sectors
Units =Number of sectors of 1* 512 =512 bytes
Sector size(logic/Physics):512 bytes/512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disc identifier: 0x000d2e86
Device boot start / end block Id system
/dev/vda1 * 2048 1026047 512000 83 Linux
Partition 1 does not end with a cylinder boundary.
/dev/vda2 1026048 62914559 30944256 8e Linux LVM
Partition 2 does not end with a cylinder boundary.
command(Help with m): d #/dev/Delete vda2 once
Partition number(1-4): 2
command(Help with m): p #/dev/Confirm that vda2 has been deleted
disk/dev/vda: 128.8 GB,128849018880 bytes
Head 16,Sector 63,Cylinder 249660,Total 251658240 sectors
Units =Number of sectors of 1* 512 =512 bytes
Sector size(logic/Physics):512 bytes/512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disc identifier: 0x000d2e86
Device boot start / end block Id system
/dev/vda1 * 2048 1026047 512000 83 Linux
Partition 1 does not end with a cylinder boundary.
command(Help with m): n #Expanded size again/dev/Create vda2
Command action
e-extension
p primary partition(1-4)
p
Partition number(1-4): 2
First sector(63-251658239,Initial value 63): 1026048
Last sector, +Number of sectors or+size{K,M,G} (1026048-251658239,Initial value 251658239):
Use the initial value 251658239
command(Help with m): p #Confirm that it was created
disk/dev/vda: 128.8 GB,128849018880 bytes
Head 16,Sector 63,Cylinder 249660,Total 251658240 sectors
Units =Number of sectors of 1* 512 =512 bytes
Sector size(logic/Physics):512 bytes/512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disc identifier: 0x000d2e86
Device boot start / end block Id system
/dev/vda1 * 2048 1026047 512000 83 Linux
Partition 1 does not end with a cylinder boundary.
/dev/vda2 1026048 251658239 125316096 83 Linux
command(Help with m): t #Change format to "Linux LVM"
Partition number(1-4): 2
Hexagon code(Display code list with L command): 8e
Region system type 2 to 8e(Linux LVM)Changed to
command(Help with m): p #Confirm that the format is "Linux LVM".
disk/dev/vda: 128.8 GB,128849018880 bytes
Head 16,Sector 63,Cylinder 249660,Total 251658240 sectors
Units =Number of sectors of 1* 512 =512 bytes
Sector size(logic/Physics):512 bytes/512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disc identifier: 0x000d2e86
Device boot start / end block Id system
/dev/vda1 * 2048 1026047 512000 83 Linux
Partition 1 does not end with a cylinder boundary.
/dev/vda2 1026048 251658239 125316096 8e Linux LVM
command(Help with m): w #Save disk changes
The partition table has changed!
ioctl()To reload the partition table.
warning:Partition table reload failed with error 16.:The device or resource is busy.
The kernel is still using old tables. The new table
Next reboot or part probe(8)Or kpartx(8)After running
Will be usable
The disks are syncing.
Reboot the machine and extend PV
# pvresize /dev/vda2
Physical volume "/dev/vda2" changed
1 physical volume(s) resized / 0 physical volume(s) not resized
Confirm that PV has been expanded
# pvscan
PV /dev/vda2 VG centos lvm2 [<19.51 GiB / 10.00 GiB free]
Total: 1 [<19.51 GiB] / in use: 1 [<19.51 GiB] / in no VG: 0 [0 ]
Expanded LV by expanded PV
# lvresize -L +10G /dev/centos/root
Size of logical volume centos/root changed from <8.51 GiB (2178 extents) to <18.51 GiB (4738 extents).
Logical volume centos/root successfully resized.
Expand the file system by the expanded LV
# xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=256 agcount=4, agsize=557568 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0 spinodes=0
data = bsize=4096 blocks=2230272, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 2230272 to 4851712
Verification. It can be confirmed that it has been expanded.
# df -h
File system size used Remaining used%Mount position
/dev/mapper/centos-root 19G 6.5G 13G 35% /
devtmpfs 485M 0 485M 0% /dev
tmpfs 496M 0 496M 0% /dev/shm
tmpfs 496M 7.1M 489M 2% /run
tmpfs 496M 0 496M 0% /sys/fs/cgroup
/dev/vdb 2.6T 1.6T 1016G 62% /storage
/dev/vda1 497M 217M 280M 44% /boot
tmpfs 100M 0 100M 0% /run/user/1000