qubes-doc/ResizeDiskImage.md
Marek Marczykowski-Górecki a56507a321 ResizeDiskImage changed
Shrinking private image.
2014-04-14 02:58:00 +00:00

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Resizing Disk Image

There are several disk images which can be easily extended. But pay attention to the overall consumed space of your sparse disk images.

Private disk image

1048576 MB is the maximum size which can be assigned to a private storage through qubes-manager.

To grow the private disk image of a AppVM beyond this limit qubes-grow-private can be used:

qvm-grow-private <vm-name> <size>

Note: Size is the target size (i.e. 4096MB or 16GB, ...), not the size to add to the existing disk.

Note2: If once the VM is started, the disk is has not been increased, you can issue in the VM's terminal:

sudo resize2fs /dev/xvdb

Shrinking private disk image (Linux VM)

This operation is dangerous and this is why it isn't available in standard Qubes tools. If you have enough disk space, it is safer to create new VM with smaller disk and move the data.

The basic idea is to:

  1. Shrink filesystem on the private disk image.
  2. Then shrink the image.

Ext4 does not support online shrinking, so can't be done as convenient as image grown. Note that we don't want to touch the VM filesystem directly in dom0 for security reasons. First you need to start VM without /rw mounted. One of the possibility is to interrupt its normal startup by adding rd.break kernel option:

qvm-prefs -s <vm-name> kernelopts rd.break
qvm-start --no-guid <vm-name>

And wait for qrexec connect timeout (or simply press Ctrl-C). Then you can connect to VM console and shrink the filesystem:

sudo xl console <vm-name>
# you should get dracut emergency shell here
mount --bind /dev /sysroot/dev
chroot /sysroot
mount /proc
e2fsck -f /dev/xvdb
resize2fs /dev/xvdb <new-desired-size>
umount /proc
exit
umount /sysroot/dev
poweroff

Now you can resize the image:

truncate -s <new-desired-size> /var/lib/qubes/appvms/<vm-name>/private.img

It is critical to use the same (or bigger for some safety margin) size in truncate call compared to resize2fs call. Otherwise you will loose your data! Then reset kernel options back to default:

qvm-prefs -s <vm-name> kernelopts default

Done.

HVM disk image

In this example we will grow the disk image of an HVM to 30GB.

First, stop/shutdown the HVM.

Then, from a Dom0 terminal (in KDE: System Tools -> Terminal Emulator) do the following:

cd /var/lib/qubes/appvms/<yourHVM>/
ls -lh root.img  (<--verify current size of disk image)
truncate -s 30GB root.img
ls -lh root.img  (<--verify new size of disk image)

The partition table and file-system must be adjusted after this change:

Windows 7

  1. Click Start
  2. type "diskmgmt.msc" - this takes you to Disk Management
  3. Right-click on your existing volume, select "Extend Volume..."
  4. Click through the wizard.

No reboot required.

FreeBSD

gpart recover ada0
sysctl kern.geom.debugflags=0x10
gpart resize -i index ada0
zpool online -e poolname ada0