[linux-lvm] can't make snapshot

[linux-lvm] can't make snapshot

[Joseph Graham]

lvcreate --size 100M --snapshot --name root_snap /dev/VolGroup00/root
-vvv 2> outfile

http://ompldr.org/vYWRqbg/outfile

This seems to be the relevent error:

        Syncing device names
        Udev cookie 0xd4d33c5 (semid 19038208) decremented to 0
        Udev cookie 0xd4d33c5 (semid 19038208) waiting for zero
        Udev cookie 0xd4d33c5 (semid 19038208) destroyed
        VolGroup00-root_snap: Skipping NODE_ADD (254,14) 0:0 0600 [trust_udev]
        VolGroup00-root_snap: Processing NODE_READ_AHEAD 256 (flags=1)
  /dev/mapper/VolGroup00-root_snap: open failed: No such file or directory
    Clearing start of logical volume "root_snap"
      /dev/VolGroup00/root_snap: stat failed: No such file or directory
  /dev/VolGroup00/root_snap: not found: device not cleared
  Aborting. Failed to wipe snapshot exception store.

Re: [linux-lvm] can't make snapshot

[Peter Rajnoha]

On 09/16/2011 12:41 PM +0100, Joseph Graham wrote:
> lvcreate --size 100M --snapshot --name root_snap /dev/VolGroup00/root
> -vvv 2> outfile
> 
> http://ompldr.org/vYWRqbg/outfile

I see:

 "Uevent not generated! Calling udev_complete internally to avoid process lock-up."

in the log. This looks like a problem we've discovered recently. See also:

  http://www.redhat.com/archives/dm-devel/2011-August/msg00075.html

That happens when namespaces are in play. This was also found while using
the Chrome web browser (which makes use of the namespaces for sandboxing).

Do you use Chrome web browser?

Peter

Re: [linux-lvm] can't make snapshot

[Peter Rajnoha]

On 09/16/2011 12:41 PM +0100, Joseph Graham wrote:
> lvcreate --size 100M --snapshot --name root_snap /dev/VolGroup00/root
> -vvv 2> outfile
> 
> http://ompldr.org/vYWRqbg/outfile

See also https://bugzilla.redhat.com/show_bug.cgi?id=727925#c11

Peter