Solved Boot Environment, something new to me and problem with a broken (?) fs

P

piggy

I do have to rebuild a machine not originally handled by me.

It has a brand new 13-release installed.

Tweaking the software for the owner, I saw it has ZFS with a unique Zpool then something happened and now the machine is not bootable anymore. It fails when it need to import the Zpool.

Digging the boot menu looking for Rescue, I saw an option called Boot Environment I do usually never seen.

In it there is a submenu with two entries: Active and bootfs. The latter do nothing, then the first is like magic. If I press the A key it goes to two different configurations named: zfs:tank/ROOT/12.0-RELEASE-up-(a date and a number).

If I choose that the machine boot to an unknown old state of the OS I didn't know and it look like a previous version of the OS then some of the data I installed is there: it changed for sure the /boot folder and the /etc folder, it is like a snapshot to my eyes.

Now, what is this Boot Environment option and what it do? Looking on the web, I didn't find much, not to say nothing and do I can use this snapshot state to repair the not bootable actual state of my same pool?
 
Thank you Sir, I'm not an expert of ZFS, to me it add a layer of confusion to the system management, and this is the deminstration. I will learn from the document suggested, for now there is some quick command I can run to have back the corrupted (i suppose) "actual" snapshot (if the name is correct or call it whatever you want)?
 
Look at the output from bectl list (I assume you managed to boot the system). It sound like someone made an boot environment some time in the past. So it's not a "brand new 13.0-RELEASE" installation but an upgrade (a fresh new install wouldn't have an old 12.0-RELEASE boot environment).
 
SirDice said:
Look at the output from bectl list (I assume you managed to boot the system). It sound like someone made an boot environment some time in the past. So it's not a "brand new 13.0-RELEASE" installation but an upgrade (a fresh new install wouldn't have an old 12.0-RELEASE boot environment).
Click to expand...
Absolutely yes, as I said I've been asked to take care of this machine, someone other installed this mess. So, to explain better, I can boot one of that "snapshot", I can't boot the actual 13-release. Do that command you suggested can be run on one of that working "snapshot" with 12-release to check the status of the broken "13-release" snapshot?
UPDATE: the command you suggested to me said "command not found".

PS: the only positive effect of this mess is I'm forced to learn something new I've never faced, in years of BSD.
 
In hindsight, you should probably focus on getting 13.0-RELEASE to boot again, and forget that old BE exists. If the name is anything to go by it's really old (12.0-RELEASE has been EoL for quite some time).

So, let's go back to this:
piggy said:
Tweaking the software for the owner, I saw it has ZFS with a unique Zpool then something happened and now the machine is not bootable anymore.
Click to expand...
What exactly did you do here?
 
You are right, it wasn't a problem with ZFS. It was a problem with a proprietary driver not working at all in 13-RELEASE.

So I learned how to mount the Zpool in a rescue environment, I used fhe install usb, and mounted the pool and removed the offending driver.

Then I learned how to handle Zpool and learned about this like snapshot Boot Environment feature, a bit incomplete in my opinion, it could be uselfull if it do something like snapshots in VMware or Virtualbox.

I also run some tests on top of ZFS and learned that is quietly fast to be a container (probably better compared to same type of file system Fedora run from defaults) then it needs a lot of memory, so I did a image of the disk and restored it on a classic UFS file system becouse this machine doesn't have a lot of memory and get rid of ZFS.

In my tests a simple zpool with his driver and under a normal load needs 60 per cents more memory compared to a normal file system. Too much for me.

So we can cal this solved.
 
ZFS likes memory that's for sure. But it'll work just fine with only 2 or 4GB of memory. You won't get stellar performance of course but it's not going to be a slouch either.
 
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