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digint / btrbk

Tool for creating snapshots and remote backups of btrfs subvolumes
https://digint.ch/btrbk/
GNU General Public License v3.0
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FAQ/Can the target btrfs disk be smaller than the source disk? #410

Closed rankaiyx closed 3 years ago

rankaiyx commented 3 years ago

Can the target btrfs disk be smaller than the source disk? As long as the target disk is large enough to accommodate the actual backup subvolumes?

In addition, can the same target btrfs disk accept sending from multiple different source btrfs disks?

digint commented 3 years ago

yes and yes.

The actual size required on the target disk is not easy to predict, and depends on the compress mount options [1] set for the btrfs filesystem on the disk. I mostly use "compress=zstd:3" for backup disks, which should give a decent balance between performance and compression ratio [2].

[1] https://btrfs.wiki.kernel.org/index.php/Compression [2] https://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git/commit/?h=next&id=5c1aab1dd5445ed8bdcdbb575abc1b0d7ee5b2e7

rankaiyx commented 3 years ago

I see. thanks