[Wolves] Fwd: Ubuntu 14.04 Nvidia upgrade woes

[Adam Sweet]

On 09/07/14 16:51, Andy Wootton wrote:
> On 09/07/14 15:09, Adam Sweet wrote:

>>> I seem to have a half-installed nvidia-331 that I can't remove. I get
>>> "stop: Unknown instance:
>>> userdel: existing lock file /etc/subuid.lock without a PID
>>> userdel: cannot lock /etc/subuid: try again later." from aptget remove
>>> and I can't install because it already 'is'.

>> I say this without any kind of warranty of course. Googling suggests
>> that subiud.lock is created by useradd to prevent multiple useradd
>> instances running at the same time. I can't believe that this should
>> be happening so removing it should be fine in single user mode while
>> you're not running anything. This may help explain:
>>
>> http://askubuntu.com/questions/459080/useradd-cannot-lock-etc-subuid-try-again-later
>>
>>
>> sudo lsof /etc/subuid
>>
>> should tell what is using the file. If nothing, then you can remove it
>> then run an update and dist-upgrade.

> Thanks. I've never had any trouble with Linux lock files so this is new
> to me. I wasn't sure if they locked by being there or by being open so I
> was afraid to delete it then not know what I needed to create. Now I
> know they're safe(ish) to delete, I can have another look. It isn't a
> problem to completely reinstall, as it's a spare machine but if I'm
> going to do that I may as well give up and get Windows. I started using
> Linux to get to know Unix but everything just works, so I've never
> really had to. I may as well try to learn something while I have the
> chance.

Lock files aren't normally safe to remove, they're created by 
application to make sure nothing interferes with what they're doing 
while they're doin something and then should be removed when it's 
finished without you needing to know about them. In this case I suspect 
something weird has happened and one has got left lying around. It may 
be a package bug that triggered during the upgrade or something.

If you can boot into single user mode and run the lsof line, before you 
do anything else, nothing else should be running and nothing should be 
using it, so you can probably safely remove it and then try to finish 
your upgrade which hopefully will resolve the issue.

Hope that fixes it for you.

Regards,

Adam Sweet

-- 

http://blog.adamsweet.org/