Converting to a btrfs Based OMV Host

Zitat von ryecoaaron

I see no reason to use btrfs for the OS drive.

Zitat von macom

I use btrfs on the OS drive mainly to be able to use snapper.

Two opposite views about the use of BTRFS on the OS,

I'm with the latest: also use BTRFS on the root drive to use snapper.

Rollback to previous states is as easy as: snapper list -a and then snapper rollback <number of the snapshot you want to use>

Very forgiving of mistakes one might make on installs/updates.

For me, it was a "set it and forget it" from the beginning. although it had to be done all on the CLI.

But after installing "Snapper" and create the configs for the snapshots (it's a good policy to reduce the amount of snapshots that are saved from default) and making some cronjobs to do scheduled scrubs, I don't touch it anymore (the BTRFS commands).

Only snag is (at least running it on RPis, don't know if it's the same for other platforms) you can not simply update the kernel and reboot: you need to update the initramfs before and change the config.txt to point to the new one.

Again, this is true on Pis

Zitat von ajaja

It is time for a new build; which includes many questions and learning.
One of my considerations is running pure btrfs.
Is there a way to OMV on a btrfs root filesystem?
Who has been/is doing so?
How can I do it?

Thank you.

Some questions were answer above and about the last one, see this about how to do it on RPis.

Maybe it can give you pointers on how to do it on x86_64 or whatever platform you'll be using:

Raspbian Btrfs root filesystem guide (2017-06) - HackMD

Zitat von ryecoaaron

I don't remember the last time I had something go bad on install or update. And if I did, they typically aren't hard to fix. You learn from fixing them as well. Rolling back just avoids the issue in my opinion and is very Windows-like.

Well, in my defense, I'm a Windows-based user,

Although I play with computers (and tried Linux several times) for a really long time, I'm not that versed in IT.

When I saw that that tool (Snapper) would help me fix things in a simple way (read sh... I make on Linux) I went for it.

I don't say it's the best but, it really works for me,

Zitat von ryecoaaron

And just out of curiousity since I see you are using lots of RPis, what do you do if you install an update and reboot but it fails to boot? Are you putting the SD card in a linux machine to revert to a snapshot?

Hasn't happen until now but, in case it happens (hope I'm at home and be able to solve it in loco) the guide I followed (the one above) makes 2 root partitions: one on ext4 and one on BTRFS.

All initial installation is done on ext4 and then cloned to BTRFS.

If things go wrong, all I need to do is change some code on the config.txt and cmdline.txt on a Windows machine (can be on linux or other) and boot it to the ext4 partition and I can fix all the BTRFS (boot another snapshot for eg) quite easy and fast.

For simplicity, I already have different copies of those txt files so it's only a matter of plug the drive to Windows; rename the proper one's; plug back the drive on the Pi and reboot.

Perhaps not easy to a newbie but not really that difficult

Zitat von ryecoaaron

I don't remember the last time I had something go bad on install or update. And if I did, they typically aren't hard to fix. You learn from fixing them as well. Rolling back just avoids the issue in my opinion and is very Windows-like.

I totally agree with that in general but here it is also about up-time. I do not want to fiddle and tinker on my main NAS. I just want it to be online. So if sth broke it makes me happy to just roll back and thats it. In that matter BTRFS on OS drive is a blessing.