Git-Mirrors/qubes-doc
1
0
Fork 0
mirror of https://github.com/QubesOS/qubes-doc.git synced 2025-11-09 06:55:41 -05:00
Code Issues Projects Releases Packages Wiki Activity

Secondary storage: fix mounting Btrfs with compression

Browse source 
Btrfs mount options are per whole filesystem, not per mountpoint. If a
filesystem (or a subvolume inside of it) is mounted a second time, the
second set of mount options such as compress= will not be applied.

https://btrfs.readthedocs.io/en/latest/ch-mount-options.html
This commit is contained in:
Rusty Bird 2025-10-02 10:21:33 +00:00
parent 27a6f3127f
commit c3f74ce704
No known key found for this signature in database
GPG key ID: 469D78F47AAF2ADF
1 changed files with 4 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

24
user/advanced-topics/secondary-storage.rst
View file

@ -66,7 +66,7 @@ Btrfs storage
^^^^^^^^^^^^^
Theses steps assume you have already created a separate Btrfs filesystem for your second drive., that it is encrypted with LUKS and it is mounted. It is recommended to use a subvolume as it enables compression and excess storage can be use for other things.
Theses steps assume you have already created a separate Btrfs filesystem for your second drive, that it is encrypted with LUKS and it is mounted. It is recommended to use a subvolume as it enables snapshotting the VM data independently of any other files that you may want to store on the filesystem.
It is possible to use an existing Btrfs storage if it is configured. In dom0, available Btrfs storage can be displayed using:
@ -177,12 +177,12 @@ First create the physical volume:
$ sudo mkfs.btrfs -L <label> /dev/mapper/luks-b20975aa-8318-433d-8508-6c23982c6cde
Then mount the new Btrfs to a temporary path:
Then mount the new Btrfs filesystem with compression enabled if desired, where ``<compression>`` can take the values ``zlib|lzo|zstd``:
.. code:: console
$ sudo mkdir -p /mnt/new_qube_storage
$ sudo mount /dev/mapper/luks-b20975aa-8318-433d-8508-6c23982c6cde /mnt/new_qube_storage
$ sudo mount /dev/mapper/luks-b20975aa-8318-433d-8508-6c23982c6cde /mnt/new_qube_storage -o compress=<compression>
Create a subvolume to hold the data:
@ -192,27 +192,11 @@ Create a subvolume to hold the data:
$ sudo btrfs subvolume create /mnt/new_qube_storage/qubes
Unmount the temporary Btrfs filesystem:
.. code:: console
$ sudo umount /mnt/new_qube_storage
$ rmdir /mnt/new_qube_storage
Mount the subvolume with compression enabled if desired, where ``<compression>`` can take the values ``zlib|lzo|zstd``. ``<subvol>`` is a Btrfs subvolume "qubes" in this example.
.. code:: console
$ sudo mount /dev/mapper/luks-b20975aa-8318-433d-8508-6c23982c6cde /var/lib/qubes_newpool -o compress=<compression>,subvol=qubes
Finally we will tell Qubes to add a new pool on the just created Btrfs subvolume:
.. code:: console
$ qvm-pool --add poolhd0_qubes file-reflink -o dir_path=/var/lib/qubes_newpool,revisions_to_keep=2
$ qvm-pool --add poolhd0_qubes file-reflink -o dir_path=/mnt/new_qube_storage/qubes,revisions_to_keep=2
By default VMs will be created on the main Qubes disk (i.e. a small SSD), to create them on this secondary drive do the following on a dom0 terminal: