Subject: bug#51787: Disk performance on ci.guix.gnu.org

From: Leo Famulari <[email-masked]>
Date: Tue, 21 Dec 2021 12:51:35 -0500

On Tue, Dec 21, 2021 at 06:26:03PM +0100, Ricardo Wurmus wrote:
> We could take this opportunity to reformat /gnu with btrfs, which
> performs quite a bit more poorly than ext4 but would be immune to
> defragmentation.  It’s not clear that defragmentation matters here.  It
> could just be that the problem is exclusively caused by having these
> incredibly large, flat /gnu/store, /gnu/store/.links, and
> /gnu/store/trash directories.

My impression was that btrfs could also become fragmented. At least,
btrfs-progrs includes a command for defragmenting. Or do I
misunderstand?