1

I ran into the following listing quite by chance:

[root@myhost /root]# cd /var/lib/lxcfs/cgroup/devices/

[root@myhost /var/lib/lxcfs/cgroup/devices]# ls -l
ls: cannot access 'devices.allow': Permission denied
ls: cannot access 'devices.deny': Permission denied
total 0
-rw-r--r-- 1 root root 0 Nov  4 10:56 cgroup.clone_children
-rw-r--r-- 1 root root 0 Nov  4 10:56 cgroup.procs
-r--r--r-- 1 root root 0 Nov  4 10:56 cgroup.sane_behavior
?????????? ? ?    ?    ?            ? devices.allow
?????????? ? ?    ?    ?            ? devices.deny
-r--r--r-- 1 root root 0 Nov  4 10:56 devices.list
drwxr-xr-x 2 root root 0 Nov  4 10:56 init.scope
-rw-r--r-- 1 root root 0 Nov  4 10:56 notify_on_release
-rw-r--r-- 1 root root 0 Nov  4 10:56 release_agent
drwxr-xr-x 2 root root 0 Nov  4 10:56 system.slice
-rw-r--r-- 1 root root 0 Nov  4 10:56 tasks
drwxr-xr-x 2 root root 0 Nov  4 10:56 user.slice

[root@myhost /var/lib/lxcfs/cgroup/devices]# 

When I googled for the reason behind those question marks above, a link suggested that this may be a sign of my HDD failing, or a corrupt file-system.

And, there are 100's of such files (with ?'s against their names) under my .../lxcfs/ directory that I've not shown above.

So, I ran an fsck.ext4 on my logical volume (where the above / filesystem resides) in the hope of finding some problems at least. But, to my surprise, I found none.

What is going on? Is this normal with LxC... LxC using some obscure Linux feature that I'm not aware of?

I'm using:

  • LxC: 2.0.5-0ubuntu1~ubuntu16.04.2
  • OS: Ubuntu 16.04
2
  • 1
    Please check with mount whether this is a virtual filesystem. It should be. As such, it does not rely on any drive.
    – Daniel B
    Commented Nov 4, 2016 at 6:24
  • Yes, indeed. I see this entry: lxcfs on /var/lib/lxcfs type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other). So, this, then, means everything's okay?!
    – Harry
    Commented Nov 4, 2016 at 7:21

1 Answer 1

1

This appears to have been a bug with lxcfs, mentioned in this message on the lxc-devel mailing list, where getting the file attributes was denied for write-only files like devices.allow.

It was reportedly fixed in later versions of lxcfs, based on this Ubuntu bug report.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .