From time to time, your data grows and a virtual machine is getting filled up. Here is a short tutorial for extending the disk capacity for KVM machines on LVM2:
First step: Poweroff the machine. This is a good situation to also update the kernel. Now you can extend the LVM2 volume in the host:
host@host01 ~ # lvextend -L 100G /dev/vg0/mysql01 WARNING: lvmetad is running but disabled. Restart lvmetad before enabling it! Size of logical volume vg0/mysql01 changed from 50.00 GiB (12800 extents) to 100.00 GiB (25600 extents). Logical volume mysql01 successfully resized root@host01 ~ #
Now you can boot up any live linux and determine the correct partition and disk:
root@rescue ~ # blkid /dev/loop0: UUID="40c4ea95-0ecc-4c51-9f3e-e49d8f62f160" TYPE="ext2" /dev/sda1: UUID="c8357796-3185-4f8f-a987-79652339bb0d" TYPE="swap" PARTUUID="00096cad-01" /dev/sda2: UUID="c0b805e3-30d0-4af2-9724-58c651e41641" TYPE="ext4" PARTUUID="00096cad-02" /dev/sda3: UUID="bb435f41-f0e4-438b-a4b0-b17874fd0504" TYPE="ext4" PARTUUID="00096cad-03" root@rescue ~ # parted /dev/sda print Model: QEMU QEMU HARDDISK (scsi) Disk /dev/sda: 107GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 1049kB 2149MB 2147MB primary linux-swap(v1) 2 2150MB 2686MB 537MB primary ext4 3 2688MB 53.7GB 51.0GB primary ext4 root@rescue ~ #
My VM has only one disk, sda1 is swap, sda2 is for /boot and sda3 is the rest, the Disk capacity amounts to 107GB, sda3 only has 51.0GB, this is the partition that I want to grow:
parted /dev/sda resizepart 3 100%
Than we need to do a fsck, otherwise we can not grow the filesystem:
root@rescue ~ # fsck.ext4 -fvC0 /dev/sda3
e2fsck 1.42.12 (29-Aug-2014)
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
67570 inodes used (2.18%, out of 3100800)
4449 non-contiguous files (6.6%)
136 non-contiguous directories (0.2%)
# of inodes with ind/dind/tind blocks: 2603/46/0
Extent depth histogram: 16320/165
6130225 blocks used (49.23%, out of 12451072)
0 bad blocks
2 large files
56433 regular files
5856 directories
2 character device files
0 block device files
2 fifos
11 links
5241 symbolic links (5030 fast symbolic links)
27 sockets
------------
67572 files
root@rescue ~ #
# the grow:
root@rescue ~ # resize2fs -p /dev/sda3
resize2fs 1.42.12 (29-Aug-2014)
Resizing the filesystem on /dev/sda3 to 25558272 (4k) blocks.
The filesystem on /dev/sda3 is now 25558272 (4k) blocks long.
root@rescue ~ #
Now you can reboot and your system should boot up and report the new size for sda3:
root@mysql01 ~ # dfc FILESYSTEM (=) USED FREE (-) %USED AVAILABLE TOTAL MOUNTED ON rootfs [======--------------] 29% 67.9G 95.8G / udev [--------------------] 0% 10.0M 10.0M /dev tmpfs [=-------------------] 1% 1.6G 1.6G /run /dev/sda3 [======--------------] 29% 67.9G 95.8G / tmpfs [=-------------------] 0% 3.9G 3.9G /dev/shm tmpfs [--------------------] 0% 5.0M 5.0M /run/lock tmpfs [--------------------] 0% 3.9G 3.9G /sys/fs/cgroup /dev/sda2 [===-----------------] 14% 419.3M 487.9M /boot tmpfs [--------------------] 0% 624.1M 624.1M /run/user/0 root@mysql01 ~ #