Recommended Btrfs Assistant configuration

[shuvashish76]

After recent experiences like these ([^1], [^2]) now I fresh installed EOS with LUKS encrypted BTRFS, GRUB.

Since I’m going in this path I’ve decided to use Snapper not Timeshift for Btrfs.

I’ve installed following packages

yay -S btrfs-assistant btrfsmaintenance

sudo pacman -S snapper snap-pac grub-btrfs

Now what to do next, what are the recommended configurations/changes needs to be done for GRUB and Btrfs Assistant?

I understand it depends on your personal preference but still can you share your way of managing them and thought process so that I can take some ideas for myself.

The subvolumes are default i.e.

@, @cache, @home, @log, @/var/lib/machines, @/var/lib/portables

[shuvashish76]

From Configuring BTRFS Assistant post:

I need the inotify-tools

sudo pacman -S inotify-tools

Then I’ve to do this:

@BluishHumility

Enable the grub-btrfs daemon so new snapshots are automatically added to the Grub menu.

sudo systemctl enable --now grub-btrfsd

Regenerate the Grub configuration file.

sudo grub-mkconfig -o /boot/grub/grub.cfg

Then this part is optional but I should do this:

@BluishHumility

You may wish to add GRUB_BTRFS_SNAPSHOT_KERNEL_PARAMETERS="rd.live.overlay.overlayfs=1" to /etc/default/grub-btrfs/config for booting snapshots read only. See here for more information about that: https://github.com/Antynea/grub-btrfs/blob/master/initramfs/readme.md#dracut-based-distros

Afterward, regenerate a new snapshot submenu.

sudo /etc/grub.d/41_snapshots-btrfs

Reboot and test that you are able to boot to a snapshot from Grub.

Few questions:

1. Why I don’t have @/.snapshots subvolume by default? Do I need to manually create it? | reference: according to @dalto it’s unnecessary. (old post though)
2. What are the @/var/lib/machines and @/var/lib/portables? Do I need snapshots of those as well?
3. Necessary to snapshot @cache and @log subvolumes? | reference : link
4. What are recommended “timeline snapshots” configuration from ‘Snapper Settings’? | reference : @dalto 's recommendation here.
5. Recommended “Btrfs maintenance setting” ?
6. Any manual intervention necessary for snap-pac? Do I need to enable it like grub-btrfs? It suggests no configuration is needed.
7. On plasma desktop Btrfs Assistant is in White theme as always no matter what global theme I set for the desktop. How to make it Dark?

@dalto 's preference/recommendations matters as he is one of the maintainer/dev of Btrfs Assistant

[Leya]

@shuvashish76

Why I don’t have @/.snapshots subvolume by default? Do I need to manually create it? | reference: according to @dalto it’s unnecessary. (old post though)

I’d need to double check but I think there should be a .snapshots subvolume. I remember seeing it in my installation.

@shuvashish76

• What are the @/var/lib/machines and @/var/lib/portables? Do I need snapshots of those as well?
• Necessary to snapshot @cache and @log subvolumes?

@dalto

They aren’t really “extra”. Every distro uses a different subvolume layout.

@cache is created because there is no reason to take snapshots of your cache. It is totally disposable data so creating that subvolume removes it from the snapshots of @.

@log is created for the opposite reason. By keeping your logs outside of @, if something goes wrong and you need to restore a snapshot of @, your logs won’t be overwritten so you can still access them and see what went wrong.

var/lib/portables and var/lib/machines aren’t created by the distro, they are created by systemd. It should be safe to just ignore those.

That being said, if you want only @ and @home you can remove @cache and @log Alternatively, if you would prefer to re-install, the subvols that the installer creates are in /etc/calamares/modules/mount.conf and you can edit that file before running the installer.

@shuvashish76

What are recommended “timeline snapshots” configuration from ‘Snapper Settings’? | reference : @dalto 's recommendation here.

There is a section with recommendations for different use cases in the btrfsmaintenance README on GitHub.

@shuvashish76

Recommended “Btrfs maintenance setting” ?

The default time settings should be fine. Just turn on the scrub and balance tasks and leave the defrag task off. I’ve activated it for all subvolumes, but I’m not entirely sure if that is necessary or if for example @ and @home would be enough. Maybe someone else could say more about that.

@shuvashish76

Any manual intervention necessary for snap-pac? Do I need to enable it like grub-btrfs? It suggests no configuration is needed.

snap-pac is set up to take snapshots of a snapper config named root out of the box. So if you created a snapper config for @ in btrfs-assistan that is named root and you only want to take snapshots of @, you don’t need to do anything else. If you want to also take snapshots of @home for example, you’d need to create additional configs for that. But strictly speaking @ should be enough.

@shuvashish76

On plasma desktop Btrfs Assistant is in White theme as always no matter what global theme I set for the desktop. How to make it Dark?

For this I actually have no idea. Maybe someone else can help

[Leya]

@shuvashish76

Then this part is optional but I should do this:

You may wish to add GRUB_BTRFS_SNAPSHOT_KERNEL_PARAMETERS="rd.live.overlay.overlayfs=1" to /etc/default/grub-btrfs/config for booting snapshots read only. See here for more information about that: https://github.com/Antynea/grub-btrfs/blob/master/initramfs/readme.md#dracut-based-distros

Afterward, regenerate a new snapshot submenu.

sudo /etc/grub.d/41_snapshots-btrfs

Reboot and test that you are able to boot to a snapshot from Grub.

I think this is no longer necessary:

@dalto

For those of you who like to boot off of you btrfs snapshots using grub, eos-dracut 1.2 now contains support for adding an overlayfs when the root filesystem is a read-only btrfs snapshot.

This does not require any special configuration.

Once you update eos-dracut and rebuild your boot images, any future snapshots will automatically support the overlay.

But I guess there is no harm in having it added either.

[shuvashish76]

@Leya

I’d need to double check but I think there should be a .snapshots subvolume. I remember seeing it in my installation.

1. Hmm…After some snapshots it automatically created multiple of them
   
   
2. Is clear
3. So - @cache and - @log is what recommended, okay​

@Leya

There is a section with recommendations for different use cases in the btrfsmaintenance README on GitHub.

4. Thanks, just checked summary. Will read their full readme.

@Leya

The default time settings should be fine. Just turn on the scrub and balance tasks and leave the defrag task off. I’ve activated it for all subvolumes, but I’m not entirely sure if that is necessary or if for example @ and @home would be enough. Maybe someone else could say more about that.

5. I was thinking same but not sure either. Thanks for your insights.
6. Ok, I’ll wait for others reply.

Actually GRUB_BTRFS_SNAPSHOT_KERNEL_PARAMETERS="rd.live.overlay.overlayfs=1" to /etc/default/grub-btrfs/config part was already there by default in latest ISO installation. Already did the sudo /etc/grub.d/41_snapshots-btrfs part. @dalto So do I need to change anything now…remove eos-dracut package or /etc/grub.d/41_snapshots-btrfs file ? Any conflicts between the two?

[Leya]

@shuvashish76

So - @cache and - @log is what recommended, okay

No actually it’s recommended to take snapshots of neither of those subvolumes. @cache is temporary stuff anyway so it’s not needed to back that up, and @log shouldn’t be backed up because when you encounter problems and revert your snapshot of @ to temporarily fix them, you usually still want to be able to look at the logs for troubleshooting. If you backup and reset the logs while reverting your root subvolume, you’ll also delete the log entries that the problem might have left, so you’ll make it harder for yourself to troubleshoot without the needed logs.

tl;dr - Just take snapshots of @ and ignore anything else. You can additionally take timed or manual snapshot of @home if you want backups of files in there, but there is no need to set snap-pac to take snapshots of @home or to revert them if you encounter problems after an update for example. For that restoring @ is enough.

@shuvashish76

Actually GRUB_BTRFS_SNAPSHOT_KERNEL_PARAMETERS="rd.live.overlay.overlayfs=1" to /etc/default/grub-btrfs/config part was already there by default in latest ISO installation. Already did the sudo /etc/grub.d/41_snapshots-btrfs part. @dalto So do I need to change anything now…remove eos-dracut package or /etc/grub.d/41_snapshots-btrfs file ? Any conflicts between the two?

I think the line is there, but it’s commented out (there is a # in front of the line which means it is ignored). Nonetheless I tested if booting from snapshots is already read-only / edits are only temporary on my identical btrfs set-up, and they are. So it definitely is working out of the box without any change needed, no matter if the line is there and uncommented by default or not.

And no you don’t need to change anything. eos-dracut and 41_snapshots-btrfs are two entirely different things and both are needed.

eos-dracut generates the initram-fs needed for booting,
41_snapshots-btrfs basically generates the sub menu that will let you select the snapshot for booting in grub itself.

[shuvashish76]

@Leya

No actually it’s recommended to take snapshots of neither of those subvolumes.

Oh okay, sorry English isn’t my 1st language. Completely misunderstood it. Thankyou for re-explaining me

@Leya

Just take snapshots of @ and ignore anything else

I read somewhere it’s better to take snapshots of @home. Of course it depends on personal preference but still…

@dalto

I would always take snapshots of /home. I think it is fairly crazy not to do so.

However, I wouldn’t restore a snapshot of /home along with a / snapshot in most cases because it may overwrite user data.

For me, snapshots of my user data are far more valuable than snapshots of /.

@Leya

I think the line is there, but it’s commented out (there is a # in front of the line which means it is ignored).

Yes you’re right, it’s ignored, I missed that​

@Leya

So it definitely is working out of the box without any change needed, no matter if the line is there and uncommented by default or not.

Yep. Interesting…is it specific to EOS only?

@Leya

And no you don’t need to change anything. eos-dracut and 41_snapshots-btrfs are two entirely different things and both are needed.

eos-dracut generates the initram-fs needed for booting,
41_snapshots-btrfs basically generates the sub menu that will let you select the snapshot for booting in grub itself.

Again thanks for the explanation​

[dalto]

@Leya

No actually it’s recommended to take snapshots of neither of those subvolumes. @cache is temporary stuff anyway so it’s not needed to back that up, and @log shouldn’t be backed up because when you encounter problems and revert your snapshot of @ to temporarily fix them

Restoring @ will not restore @log and @cache will not cause those to be restored even if you take snapshots of them.

That being said, I see no value in taking snapshots of @cache. For @log, I suppose it is personal preference, I would not take snapshots of it, personally.

@Leya

Just take snapshots of @ and ignore anything else.

I would strongly recommend taking snapshots of @home. Don’t use snap-pac for those snapshots, just take them on a schedule.

[shuvashish76]

@dalto

Don’t use snap-pac for those snapshots, just take them on a schedule.

So at this point your suggestion is to completely remove that package?

sudo pacman -Rns snap-pac

The reason I installed it because Eric Dubois mentioned in some EOS + Btrfs videos. https://github.com/erikdubois/arcolinux-nemesis/blob/master/AUR/install-snapper.sh (I installed as pacman though)

They also installed snapper-tools and snapper-support but I didn’t because of your this comment.

@dalto

I don’t recommend using *-git packages unless absolutely needed because you are essentially testing development code in that case. For most people snap-pac is in the repos and will work for most people.

@SenseiR6

yay -S btrfs-assistant
yay -S snapper-tools

For most use cases, it should be sufficient to install either snapper-tools or btrfs-assistant since they have a tremendous amount of overlap.

@SenseiR6

yay -S snapper-support

I personally think it is better to set this up yourself instead of installing snapper-support. I don’t see much value in installing the custom path unit anymore and since we use dracut all the mkinitcpio stuff in there has no benefit

[dalto]

@shuvashish76

So at this point your suggestion is to completely remove that package?

No, not at all. snap-pac is taking snapshots of @ before and after each update.

I am saying that for @home, you should take snapshots on a schedule. To be honest, I would also take snapshots of @ on a schedule but those are in addition to your pacman snapshots.

@shuvashish76

They also installed snapper-tools and snapper-support

You have already done the setup, so there would be not point in installing snapper-support at this point.

snapper-tools is just another front-end for snapper. An opinionated one. It is up to you if you want it or not. You definitely don’t need it.

[shuvashish76]

@dalto

No, not at all. snap-pac is taking snapshots of @ before and after each update.

I am saying that for @home, you should take snapshots on a schedule. To be honest, I would also take snapshots of @ on a schedule but those are in addition to your pacman snapshots.

Ahh now I get it.

@dalto

I would strongly recommend taking snapshots of @home. Don’t use snap-pac for those snapshots, just take them on a schedule.

I thought snap-pac only able to take snapshots of @ not @home. So I need not to change anything. And yes taking snapshots of @home on schedule with snapper through Btrfs Assistant.
Your intention of these @home snapshots are purely for data recovery purpose not restore correct ?

@shuvashish76

On plasma desktop Btrfs Assistant is in White theme as always no matter what global theme I set for the desktop. How to make it Dark?

I think all my doubts are clear for now, besides this one.

[dalto]

@shuvashish76

Your intention of these @home snapshots are purely for data recovery purpose not restore correct ?

Yes.

@shuvashish76

On plasma desktop Btrfs Assistant is in White theme as always no matter what global theme I set for the desktop. How to make it Dark?

You need to set the theme of the root user to be dark. One easy way to do this is using a tool like konsave.

[Leya]

@dalto

I would strongly recommend taking snapshots of @home. Don’t use snap-pac for those snapshots, just take them on a schedule.

@shuvashish76

I read somewhere it’s better to take snapshots of @home. Of course it depends on personal preference but still…

You both somehow seem to have missed the second part of my comment about snapshoting @home

@Leya

tl;dr - Just take snapshots of @ and ignore anything else. You can additionally take timed or manual snapshot of @home if you want backups of files in there, but there is no need to set snap-pac to take snapshots of @home or to revert them if you encounter problems after an update for example. For that restoring @ is enough.

@dalto

I would strongly recommend taking snapshots of @home. Don’t use snap-pac for those snapshots, just take them on a schedule.

So yeah that’s basically what I also recommended, but it’s good see that you’re recommending the same

@shuvashish76

I thought snap-pac only able to take snapshots of @ not @home. So I need not to change anything.

snap-pac is able to take snapshots of other subvolumes, it’s just not set up to do so by default. Just make sure your snapper config for @ is called root and it will take snapshots of this config out of the box. Everything else you need to configure manually. So you don’t need to do anything else to not make it take snapshots of @home

@dalto

Restoring @ will not restore @log and @cache will not cause those to be restored even if you take snapshots of them.

That being said, I see no value in taking snapshots of @cache. For @log, I suppose it is personal preference, I would not take snapshots of it, personally.

And of course this is right too, my wording here was a bit off and the explanation not detailed enough. Was typing this from my phone, so please forgive me

Happy we were able to help and clear things up for you.

[Darius]

@dalto

You need to set the theme of the root user to be dark.

Why not just log in as root, set the theme to dark and log out again? Nothing else should be disturbed, right?

[dalto]

@Darius

Why not just log in as root, set the theme to dark and log out again?

You should never, ever, log into your DE as root.