Ext4 vs. Btrfs performance on Qubes OS installs

General Discussion
41

Blivet said it wouldn’t accept my Btrfs-on-LUKS partition unless I let it re-format it. If I let it re-format, I lose no-holes and xxhash. :person_shrugging:

I’m not sure, but I think in some cases Blivet or Anaconda custom will also re-format LUKS in addition to the fs. It seemed like once my 4096b sector LUKS changed back to 512b. I think in that case when you click ‘Done’ it asks you for a passphrase even though you’ve already unlocked your existing LUKS.

As for the advantage of having root on the custom fs, I don’t think there is much. The good part is Qubes lets me set up a vm pool the way I want.

42

in fc32 (4.1) shouldn’t be like that, also i dont know how you do that but if you want to try.

after encrypt drive and do mkfs.btrfs in shell with volume name is qubes_dom0
do refresh and rescan in anaconda, click blivet and done.

you should see your btrfs volume there, what you have to do is right click on that volume, click new,
name: root
mount point: /

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43

I’ll take your word for it, as I was looking at the gears menu not right-clicking. For now I’ll be using the XFS root + custom Btrfs pool for domU related tests.

For testing vm startup times, I might prefer a different approach than starting the same vm 3X since that leans heavily on cache and doesn’t mirror usage patterns (after the system boots, at least).

I’m thinking have 3 different vms based on 3 different templates that are not de-duped or reflink-cloned. Each startup runs Firefox browser, then shuts down the vm.

44

In the 4.2 RC2 installer is it possible to choose btrfs? Is this option available?

45

Yup, same as it was in R4.0 and R4.1.

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46

This can be found under custom partitioning alongside LVM. The default is a single LUKS container encompassing SWAP and TLVM pools. (Thin LVM or fat LVM: that is: preallocated Logical Volumes)

Note that BRTFS partition scheme under QubesOS is still 2 LUKS containers, one for the pool and one for swap.

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