A Linux virtual machine I use for hosting containerized services in my home lab recently ran out of disk space. I decided to allocate more disk space to it since I had plenty to spare. It turns out that when I'd created the VM, I'd given the virtual hard drive only 200 GB but sometime between then and now, I'd increased the allocation to 1 TB. Strangely, I never checked to see if the VM was using the full terabyte! Frustrated that it wasn't, I set about rectifying the situation.
I am running the VM on a QNAP NAS using QNAP's QOS's Virtualization Station. This is a basic VM manager that uses qemu under the hood. It's adequate for my needs and has a simple control panel for administration. In my case, sometime in the past, I'd turned off the VM and adjusted the slider for the virtual disk to increase the reserved disk space on the host.
In my case, I've a single VM with a single virtual hard disk.
It sees one disk, /dev/vda, and has an LVM-managed volume at /dev/mapper/ubuntu--vg-ubuntu--lv.
While df -h shows the volume having a 200 GB capacity, parted shows /dev/vda3 having 1 TB.
Let's expand to fill the space.
First, I verified all of the assumptions using df -h, fdisk -l, and parted, running print devices in the latter.
N.b., I run in regular user mode so the below will have sudo prepended where root privileges are needed.
I'm also only showing the relevant parts of the output, noting elided output with ….
colin@hotdog:~$ df -h
Filesystem Size Used Avail Use% Mounted on
…
/dev/mapper/ubuntu--vg-ubuntu--lv 196G 160G 26G 87% /
…
/dev/vda2 974M 205M 702M 23% /boot
colin@hotdog:~$ sudo fdisk -l
…
Disk /dev/vda: 1000 GiB, 1073741824000 bytes, 2097152000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 6E9BC534-3F72-4EBC-9244-5D95C5A7D186
Device Start End Sectors Size Type
/dev/vda1 2048 4095 2048 1M BIOS boot
/dev/vda2 4096 2101247 2097152 1G Linux filesystem
/dev/vda3 2101248 2097149951 2095048704 999G Linux filesystem
Disk /dev/mapper/ubuntu--vg-ubuntu--lv: 200 GiB, 214748364800 bytes, 419430400 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
…
colin@hotdog:~$ sudo parted
GNU Parted 3.3
Using /dev/mapper/ubuntu--vg-ubuntu--lv
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print devices
/dev/mapper/ubuntu--vg-ubuntu--lv (215GB)
/dev/sr0 (952MB)
/dev/vda (1074GB)
(parted) print list
Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/ubuntu--vg-ubuntu--lv: 215GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags
1 0.00B 215GB 215GB ext4
…
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 1074GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 2097kB 1049kB bios_grub
2 2097kB 1076MB 1074MB ext4
3 1076MB 1074GB 1073GB
The rest of this went very easily for me and resulted in no downtime.
Resize the partition for good measure using parted.
colin@hotdog:~$ sudo parted
GNU Parted 3.3
Using /dev/mapper/ubuntu--vg-ubuntu--lv
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) select /dev/vda
Using /dev/vda
(parted) resizepart
Partition number? 3 <----- Manually typed based on output of above "print list"
End? [1074GB]? <----- I just hit ENTER to confirm.
(parted)
Information: You may need to update /etc/fstab.
Resize the physical volume in LVM's eyes:
colin@hotdog:~$ sudo pvresize /dev/vda3
[sudo] password for colin:
Physical volume "/dev/vda3" changed
1 physical volume(s) resized or updated / 0 physical volume(s) not resized
Extend the logical volume in LVM's eyes to fit the whole physical volume:
colin@hotdog:~$ sudo lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
Size of logical volume ubuntu-vg/ubuntu-lv changed from 200.00 GiB (51200 extents) to <999.00 GiB (255743 extents).
Logical volume ubuntu-vg/ubuntu-lv successfully resized.
Now, resize the filesystem. This command took several minutes:
colin@hotdog:~$ sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
resize2fs 1.45.5 (07-Jan-2020)
Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required
old_desc_blocks = 25, new_desc_blocks = 125
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 261880832 (4k) blocks long.
Lastly, verify that df -h shows the correct volume size:
colin@hotdog:~$ df -h
Filesystem Size Used Avail Use% Mounted on
…
/dev/mapper/ubuntu--vg-ubuntu--lv 983G 160G 781G 17% /
…
/dev/vda2 974M 205M 702M 23% /boot
…
That's what I expect, so I'm done. Hooray!