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I am trying to follow another post on Ask Ubuntu (Can I have a swapfile on btrfs?, specifically Pilot's answer) and I have run into the problem that I have no idea what @home means. The paragraph I'm confused by is below:

Lets assume that the current swap is already off, the / is on /dev/sda1 and Ubuntu is installed with / on @ subvolume and /home is on @home subvolume.

I am not sure what "/home is on @home", or even "/ is on /dev/sda1" and "/ on @" mean.

Can someone explain this to me?

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    Welcome to AskUbuntu. The @ refers to a subvolume, which is one of the key aspects of the file system 👍🏻
    – matigo
    Dec 4, 2022 at 22:56
  • Ah that makes sense, thank you. I'd never seen that before (probably because I'd never messed around with the file system before). Anyways, I managed to figure out the rest of the answer on that post I linked. For posterity, the problem I was having was that I was using /dev/nvme0n1p2 instead of /dev/nvme0n1p3 to represent my ssd
    – Richatd_q
    Dec 5, 2022 at 3:58
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    @matigo, the use of @ in he context of btrfs subvolumes is, afaik, just a convention, used by Ubuntu (and perhaps Debian), but for example not on Fedora. You can use the character to name a subvolume as you can use it in a directory name.
    – vanadium
    Dec 5, 2022 at 8:01
  • @vanadium good to know. Thank you 👍🏻
    – matigo
    Dec 5, 2022 at 8:14

1 Answer 1

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The @ symbol doesn't have any special meaning. @home is just a name of a btrfs subvolume. It can be named differently.

Ubuntu maintainers chose to name @ subvolume to mount / and @home to mount /home. I followed the same logic and chose to call a subvolume for a swap file @swap.

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