If the disk is completely full, you will get an `Out of disk space` error that may crash your system because Dom0 does not have enough disk space to work.
If you run `df -h`, it only shows the information in the `root` line (which is already included in the `pool00` line).
As you can see, the `sudo lvs | head` command includes additional important columns `Data%` and `Meta%`, shown in the above example to have the values 89% and 69% respectively.
If your system is able to boot, but cannot load a desktop environment, it is possible to login to dom0 terminal with Alt + Ctrl + F2.
4. Remove some unneeded files in dom0 home (if you have any, most likely not). Also look for unneeded files in `/var/log` in dom0, and `/var/log/qubes`.
The above steps applies to old VM disks format. These steps may work on Qubes 4.0, but are not default anymore. By default, Qubes 4.0 now uses LVM. The equivalent steps are:
1. Get a list of VM disks using `sudo lvs`.
2. Use `sudo lvremove qubes_dom0/<name>` to remove backup copies of some less important VMs -- entries with `-back` in their name.
3. If that isn't enough, remove actual disks of less important VMs. NOTE: You will lose the data of that VM, but your system will resume working.
Since `qvm-console-dispvm` requires working graphical user interface login, you must first free enough space to be able to start a VM and login to graphical UI.
[Resizing a volume](/doc/resize-disk-image/) in the Qubes interface should be a straightforward process.
But sometimes, an attempt to resize will look like it worked, when it in fact fails silently.
If you then try the same operation in the dom0 console using the `qvm-volume extend` command, it fails with the error message: `resize2fs: Permission denied to resize filesystem`.
This error indicates that a `resize2fs` will not work, unless `fsck` is run first.
Qubes OS utilities cannot yet handle this case.
To fix this issue:
1. In the dom0 terminal get a root console on the vm (eg. sys-usb) with:
2. Unmount everything mounted on the private volume `/dev/xvdb partition`.
There are typically several mounts listed in `/etc/mtab`.
3. When you attempt to unmount the `/home` directory using the `umount /home` command, you will encounter an error because there are processes using the `/home` directory. You can view a list of these processes with the `fuser` command:
~~~
fuser -m /home
~~~
Kill these process until they are all gone using `kill <process ID>`.
4. Finally, run:
~~~
umount /home
fsck /dev/xvdb
resize2fs /dev/xvdb
~~~
After restarting your VM, everything should now work as expected.
The private volume size shown externally in the VM's settings interface is the same as that seen within the VM.
