Arch Linux

Reded

Member

From: Manchester, England

Registered: 2012-02-21

Posts: 242

Btrfs and subvolume mounting questions [SOLVED]

Hey all,

I'm considering giving btrfs a try on my Arch machine, I know I'm not the first! However, I'm a bit confused as to the whole conversion process (I don't really want to reinstall). I want to try and get a similar setup to how OpenSUSE does it, which is one big btrfs drive with folders within root split up by subvolumes. /home is on a seperate drive, and so a similar setup will be done there (with each user having a seperate subvolume).

My confusion comes from what seems to be conflicting (well, not conflicting, just me reading them wrongly) mounting setups within /etc/fstab. Let's say, for example, I have a btrfs partition, with root in a subvolume. I then have /var within a subvolume inside that one. Will my /etc/fstab have to reflect that? Or will the btrfs magic take care of that for me? That is, I will have my root subvolume written in fstab (as per these instructions  https://wiki.archlinux.org/index.php/Bt … subvolume) and the other subs within that will just be taken care of by btrfs and not require an entry within fstab.

I'm sorry if this is a stupid question, but it's one I can't seem to find a definitive answer to.

Thanks all!

Last edited by Reded (2014-03-30 02:18:28)

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WorMzy

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From: Scotland

Registered: 2010-06-16

Posts: 11,896

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Re: Btrfs and subvolume mounting questions [SOLVED]

If you mean you have ${BTRFSROOT}/root-fs and ${BTRFSROOT}/root-fs/var then you won't need to mount var separately, it's a nested subvolume.

However, if you have ${BTRFSROOT}/root-fs and ${BTRFSROOT}/var then you will need to mount the var subvolume to the appropriate place.

EDIT: Also, I would advise against converting unless you have no other option. Conversions often have problems.

Last edited by WorMzy (2014-03-29 15:33:11)

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Reded

Member

From: Manchester, England

Registered: 2012-02-21

Posts: 242

Re: Btrfs and subvolume mounting questions [SOLVED]

Thanks for clearing that up, and my conversion went (mostly) well It seems like an obvious question now I've actually done it.

My other option was a reinstall, which is mostly a matter of pride, but I agree that converting wasn't exactly smooth sailing!

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"Some humans would do anything to see if it was possible to do it. If you put a large switch in some cave somewhere, with a sign on it saying "End-of-the-World Switch. PLEASE DO NOT TOUCH", the paint wouldn't even have time to dry."