I’m attempting a new install. I want to use btrfs with swapfile.

Do I need to disable compression on my swap subvolume?

Is there anything else I should keep in mind for fstab if I want to, say, not keep track of my Downloads folder when snapshotting?

Here is my fstab:

LABEL=arch@btrfs        /               btrfs           rw,relatime,discard=async,space_cache=v2,subvolid=256,subvol=>

LABEL=arch@btrfs        /home           btrfs           rw,relatime,discard=async,space_cache=v2,subvolid=257,subvol=>

LABEL=arch@btrfs        /var/cache/pacman/pkg   btrfs           rw,relatime,discard=async,space_cache=v2,subvolid=259>

LABEL=arch@btrfs        /var/log        btrfs           rw,relatime,discard=async,space_cache=v2,subvolid=258,subvol=>

LABEL=arch@btrfs        /.snapshots     btrfs           rw,relatime,discard=async,space_cache=v2,subvolid=260,subvol=>

LABEL=arch@btrfs        /swap           btrfs           rw,relatime,discard=async,space_cache=v2,subvolid=263,subvol=>

LABEL=efi@fat32         /efi            vfat            rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=asci>

/swap/swapfile          none            swap            defaults        0 0
  • @bazsyEnglish
    6•11 months ago

    Do I need to disable compression on my swap subvolume?

    Short: No

    Long: it doesn’t matter when mounting multiple subvolumes of the same btrfs partition the options from the first one (usually /) will apply to all. So even if you disable it, that will be ignored.

    The old way of creating swap shows the chattr +C line which disables CoW. The same method should work for your Downloads folder since CoW is needed for snapshotting.