Using different filesystem types on a Linode
The Linode Manager only lets me create a disk in the following formats: ext4, ext3, swap, raw, and initrd. Is it risky to use a different type than those? What is the best way to use a type of filesystem not on that list, such as btrfs? Are there any downsides?
If you're trying to use a filesystem type that we do not offer then you'll want to use a raw disk. This is because a Linode treats a raw disks differently than the other types (ext3, ext4).
You could create an ext4 disk and reformat it, but that will introduce compatibility issues with the Manager (resizing, Backups, etc…) and introduces more work for you. Given that, you may as well start with a raw disk. Keep in mind that raw disks do have limitations:
- They cannot be resized down, only up.
Resizing will have to be performed in two steps:
You will not be able to use our Backups service. Any data you need to keep backed up would have to be rsynced to an ext4 disk.
The Manager will not display your real type, it will only ever show the disk type as raw.
I'm hoping to create a Debian VPS from scratch, using btrfs for the root filesystem if possible (just like Linux Mint 19 can now do, if you choose "btrfs" as the filesystem, during a fresh install to a laptop).
Note that Linux Mint 19 will make 2 subvolumes automatically (if you chose "btrfs" as your filesystem, which is currently not the default), called "@" and "@home". All the contents of /home are inside the "@home" subvolume, and all the rest of the directories in / are inside the "@" subvolume. These subvolumes need to have been created in order to have snapshots of them be possible.
Then the nice GUI tool "Timeshift" automates making periodic snapshots of those 2 subvolumes (like, on a daily, weekly, or monthly basis, and you set how many snapshots to retain in an automatically rotating pattern). It works like Apple TimeMachine, letting you roll back to older snapshots in case some sort of upgrade gets botched.
Linode, please offer a service like this, where a default install gives btrfs snapshots that can be rolled back. I would prefer this to be in Debian.
You can configure that yourself, the custom distro guide has more implementation details:
I'm using my Linode with BTRFS formatted rootfs. Here is my HOWTO for further references: https://github.com/ceremcem/linode-notes#converting-rootfs-to-btrfs