[ISO Install] BTRFS on SSD as Filesystem autodefrag enabled


a other “Bug” maybe, or something a investigation/discussion is worth.

Choosing BTRFS as Filesystem in the ISO Installer enables autodefrag on a SSD. But defragmenting a SSD isnt needed, and is indeed contraproductive because you didnt get any performance benefits (it could make it slower indeed) and only wear out the SSD more.

Found it, because i installed my VM just for fun/trying with BTRFS.

It should be consider to disable this on SSD installation.

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Are you referring to auto trim?

btrfs autodefrag isn’t exactly the same as traditional disk defragmentation.

There is a lot of conflicting information on if you should use btrfs autodefrag on an SSD. There do seem to be some use cases where using it is beneficial.

That being said, the reason it is there is due to an upstream limitation in Calamares, the installer we use. It has the ability to add options for SSDs but not for HDDs.

I recently submitted a PR which addresses that issue along with some others.

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Why conflicting? https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-filesystem

Its says exactly what it do. Its defrag the data exactly like you would with any tool on any OS on a normal HDD.

And it isnt any wrong about it. If your using a HDD. But on a flash based memory this is controversial.

Sadly, i dont know how to post on the mailinglist from BTRFS devs to ask them what the official way is.

No. the autodefrag option.

I don’t have the time to do the search for you at this moment but if you search for btrfs autodefrag ssd there are endless arguments and discussions some of which provide some data.

That being said, I agree with you that it shouldn’t be the default on SSDs, however the installer doesn’t currently have a way to do that but hopefully will soon.


Nice. i have a whole other experience. Maybe because i dont use google :grinning_face_with_smiling_eyes:

I didnt find a single one, asking the same question. Only one:


And this im still reading. Its hard to read so compressed in a small space.

I understand.