Issue #635: F34 Change: Enable btrfs transparent zstd compression by default - release-notes

fedora-docs / release-notes

#635 F34 Change: Enable btrfs transparent zstd compression by default

Closed 2 years ago by pbokoc. Opened 3 years ago by bcotton.

This issue tracks the release note for the following Fedora Change:

https://fedoraproject.org/wiki/Changes/BtrfsTransparentCompression

If you own this change, please add additional information here that we should communicate to Fedora users. Specifically, please consider:

New features available because of this change - pick 2 or 3 that are important
Considerations for users of previous releases of Fedora (upgrade issues, format changes, etc.)
Links to any upstream Release Notes
If this helps Fedora be a superior environment for our target audiences, please explain how so that we can emphasize this.

Your notes to us do not need to be formally written. We will edit them and add details as needed. This is a way for you to ensure that we know what is critical about your change.

If you want to write this release note, then:

Assign this issue to yourself
Check the wiki page linked above, find out what the change is about
Determine whether the change actually made it into the release or not[0]
Write a draft release note using that information against the correct branch here, in Pagure. (or see below)
Get in touch with the contact person/people listed on the wiki page, either through IRC or e-mail, and ask them to check your draft for technical accuracy
Submit your Release Note as a PR to this repository.

Once you're done with the above, make sure to either commit the relnote to an appropriate section of the Release Notes book, or, if you're not familiar with Git, AsciiDoc, or whatever else, just add it to this issue as a comment and let pbokoc[1] know that you're done with this one and you'd like the note included. Be sure to do this at least one day before the final release (October 29 according to the current schedule). Also make sure to do this even for relnotes that haven't been checked by the change owner.

[0] You can do that by asking the change owner listed on the wiki page; alternatively you can infer it by checking the tracker bug (linked in Wiki) in Bugzilla and looking at its status; see bug comments for details. Ask someone on the mailing list or on IRC if you're not sure.
[1] In #fedora-docs on FreeNode (UTC+1 timezone, online mostly during the day on weekdays), or pbokoc @redhat.com if you can't get a hold of me on IRC.

chrismurphy commented 3 years ago

On variants using btrfs as the default filesystem, enable transparent compression using zstd as a file system wide mount option. This feature is enabled by default on new clean installations.

Compression saves space and can significantly increase the lifespan of flash-based media by reducing write amplification. It can also increase read and write performance.

The feature can be enabled anytime, including before or after upgrading, by editing '/etc/fstab', and adding compress=zstd:1 mount option to the / mount point line.

The feature can be disabled by editing '/etc/fstab' and removing the 'compress' mount option.

Please see the Enable btrfs transparent zstd compression by default feature page for more details and FAQ:
https://fedoraproject.org/wiki/Changes/BtrfsTransparentCompression#Detailed_description

Edited 3 years ago by chrismurphy

Metadata Update from @mareksu:
- Issue assigned to mareksu

2 years ago

mareksu commented 2 years ago

Hi @chrismurphy,

If you happen to have a moment before the Fedora 34 release, could you please review this last-minute Btrfs release note?

If you can't, don't worry about it.

Thanks!

.The root Btrfs file system now uses compression

New Fedora installations now enable transparent compression on the root Btrfs file system, including all its subvolumes. The default compression algorithm is `zstd:1`. This change has no effect on Fedora variants that do not use Btrfs in their installation.

The benefits of the compression include:

* The compression saves storage space and can significantly increase the lifespan of flash-based media, such as SSDs, by reducing write amplification.
* The compression can increase read and write performance.

You can configure the Btrfs compression on an existing installation:

. Edit the `/` mount point in the `/etc/fstab` file.

** To enable the compression, add the `compress=zstd:1` option to the mount point.
** To disable the compression, remove the `compress=zstd:1` option from the mount point.

. Remount the file system:
+
----
# mount -o remount,compress=none /
----

For more information about the Btrfs compression, see link:https://fedoraproject.org/wiki/Changes/BtrfsTransparentCompression[Changes/BtrfsTransparentCompression]

chrismurphy commented 2 years ago

Looks good to me.

The Remount section might show the two remount possibilities (maybe it's obvious, not sure), depending on whether to enable or disable the feature:

# mount -o remount,compress=compress=zstd:1 /
# mount -o remount,compress=none /

Of course, they can just make the /etc/fstab changes and reboot.

Edited 2 years ago by chrismurphy

mareksu commented 2 years ago

Ah, good point, I missed that option.

I'm going to change the command to just mount -o remount /. I believe that applies whatever is configured in /etc/fstab at that time. If that isn't the case, please correct me.

chrismurphy commented 2 years ago

It doesn't actually. The remount will leave already set options, including compress and ssd and various others, unless their antonym mount option is explicitly used, e.g. compress=none and nossd.