BTRFS: open_ctree failed after ubuntu image deploy

[Sebastian Roth]

@Quazz Good find man! Although I am wondering if this is the exact same issue as they are talking about an issue with “lzo compressed btrfs volumes” which @Oleg does not seem to have according to his /etc/fstab…

I had a bit of time while I was waiting for some other installations today so I setup Ubuntu 16.04 server (should be close enough to the scenario with Oleg’s Ubuntu desktop), booted it a couple of times without an issue, uploaded an image and deployed it again. My Ubuntu server is coming up and seems normal but taking a look at /var/log/kern.log I see a lot of these messages:

BTRFS error (device sda3): bad tree block start 0 40345712
BTRFS error (device sda3): bad tree block start 0 40484864
BTRFS error (device sda3): bad tree block start 0 40091648
BTRFS error (device sda3): bad tree block start 0 40108032
BTRFS error (device sda3): bad tree block start 0 40042496
...

Notice the different numbers at the end of the lines. I am not sure what that means. Guess we need to do some more research on this as it does not seem to be a showstopper in my case. I don’t see the BTRFS: open_ctree failed but I have some other btrfs related messages:

BTRFS info (device sda3): read error corrected: ino 1 off 125304832 (dev /dev/sda3 sector 261120)
BTRFS info (device sda3): read error corrected: ino 1 off 125308928 (dev /dev/sda3 sector 261128)
BTRFS info (device sda3): read error corrected: ino 1 off 125313024 (dev /dev/sda3 sector 261136)
BTRFS info (device sda3): read error corrected: ino 1 off 125317120 (dev /dev/sda3 sector 261144)

Anyone keen to dig into this and take a look at the partclone code as well. I’d love to but I guess I won’t find the time in the near future.

[Oleg]

@Sebastian-Roth
Thanks for your suggestion! for a normal use yours is better - in our case we have only a couple applications which are storing their data in the /opt. For sda2 and sda3 I think I will follow your suggestion.
Yes your right - in my setting I don’t have the “lzo compressed” options in the fstab.
In your case the system comes up in my not. Will look further today to confine the issue.

I think if it’s a partcone “code-issue”, the solution could take a while?! I’m asking because then I have to switch to another filesystem.

[Tom Elliott]

I feel I should at least kind of chime in a little bit.

The issue here is not in any way, shape, or form, related to the message as described in the title. The “random: nonblocking pool is initialized” is simply a kernel debug statement just telling you the pool to randomize elements in a non-blocking form has been initiated. This is NOT what is causing the failure to boot after upload, nor is it impeding with BTRFS in anyway.

I think @Quazz is right, at least in that we can perform a btrfs filesystem check. I doubt it will fix anything though. See, @Sebastian-Roth has successfully imaged the system using similar layout as yours, and while there are a few concerning error messages, the system is still operation. Maybe something else is causing issues?

[Sebastian Roth]

@Tom-Elliott said in Upload image "random: nonblocking pool is initialized":

See, @Sebastian-Roth has successfully imaged the system using similar layout as yours, and while there are a few concerning error messages, the system is still operation. Maybe something else is causing issues?

While you’re right that my system seemed to boot up properly after cloning I am still very concerned about those messages I posted. I just started up the system again. Booted ok, but I get a couple of these bad tree block start messages every minute now. I am trying to get in contact with the clonezilla developers about this as I think this is not a very special case and will hit is from time to time. I don’t think we should do raw imaging with btrfs filesystems just to circumnavigate this issue.

PS: Tom is right about the title. @Oleg would you mind changing the title to something appropriate?

[Quazz]

@Sebastian-Roth Have you tried a fsck? There might be some useful info coming out of that if anything, although this seem like a partclone issue, more info is always nice.

[Oleg]

@Sebastian-Roth
no problem - change the topic in something more related to the discussed issue.

today I tried to clone that image with another fstab-mount-options. I remove discard because I read that this option should not be used with BTRFS and also tried with clear_cache and nospace_cache but with no success.

[Sebastian Roth]

@Quazz said in Upload image "random: nonblocking pool is initialized":

Have you tried a fsck? There might be some useful info coming out of that if anything, although this seem like a partclone issue, more info is always nice.

There are about a dozen or so of btrfs-tools (like btrfs, btrfs-find-root, btrfs-debug-tree and some more) to examine and fix those kind of filesystems. Unfortunately I haven’t played with those tools before and don’t really know enough about btrfs to find out what is causing this BTRFS: open_ctree failed.

[Tom Elliott]

@Oleg what if you use those added arguments to the host kernel args?

[Sebastian Roth]

@Oleg

Hi,

Yes, Thomas Tsai is working on that.
BTRFS code base is under heavy development, so it changes very fast. Of
course we have to catch that.
Once Thomas has improved that, we will release another release.
Thanks.

Steven

On 6/17/2016 PM 03:48, sebastian.roth wrote:

Hi Steven,

I am wondering about if you have heard about any known issues with
partclone (0.2.88) and BTRFS?

After cloning a fresh installed Ubuntu system with btrfs the root
partition seems crooked.

https://forums.fogproject.org/uploads/files/1465402138541-img_20160608_175505.jpg

More Information:
https://forums.fogproject.org/topic/7700/btrfs-open_ctree-failed-after-ubuntu-image-deploy/6?page=2

Thanks in advance!

Cheers,
Sebastian

[Oleg]

@Sebastian-Roth
ok. That means we need to wait now until it’s solved in partclone.

Thanks for the information!

[Sebastian Roth]

@Oleg said:

ok. That means we need to wait now until it’s solved in partclone.

Yes. As soon as there is a new partclone version out (please inform us if you hear about it first) Tom can include it into the init’s and hopefully we should be fine then. But I don’t know when that will be.