[ubuntu-uk] hard disk problem ?

Avi lists at avi.co
Thu Jul 7 20:02:54 UTC 2011

ajp at princeswalk.fsnet.co.uk wrote:
> I know that Ubuntu does have a warning message when disk space is low
> (from my eeepc with only a 4GB SSD!), but do I understand that there
> is also a 'userspace' limit of, say, 90% of the disk, in which case,
> does the warning apply to the whole disk, or just the userspace?

"Userspace" refers to where the applications are running; it's a
concept that applies to the running software, and has nothing really to
do with hardwre, so it applies to the whole disk - all volumes
configured so.

> And also, which limit would apply if the user assumes Admin rights
> such as with Update Mananger? I think we need to have the rules spelt
> out to fully satisfy the detractors (possibly in an article somewhere,
> like in Linux Journal).

Update Manager would be permitted to 'overfill' the drive. But if your
users are too [stupid|untrusted|unprivileged] to be able to notice that
they're about to fill up ~, they're not running updates themselves,

> There are also question about what to do when the userspace limit is
> reached. In my old Unix days, it was easy to call up a new terminal
> and log in as root. 

It still is. In Ubuntu you have to have set a root password first, but
ctrl+alt+F[1 .. 7] gets you new TTYs for logging on to, or just start
an xterm. Or, more ideally, ssh in from your desk.

> It was easy to even get the user to do that. 

Which would appear to obviate the point somewhat.

> I assume in Ubuntu one would have to reboot into Recovery mode. Can
> the user easily reboot when the disk is full? Would an admin want to
> tell the user how to go into Recovery mode? 

It depends what you mean by 'the disk is full'. If you're deploying to
the sorts of users most people mean by 'in the work place[0]' then your
users are only able to overfill their home directories, and that
doesn't break anything. Things will complain, so the user will delete
some files and they will stop complaining.

I'm not really sure how to make everything go horribly wrong by filling
a partition. The most dangerous sounding one I can think of is /var, but
even that only irritates whatever's writing to it - services tend to
cope reasonably well with waiting for someone to ssh in and delete some
log files, I doubt desktop apps/servers are particularly less polite.

> These are just some thoughts about what is needed for Ubuntu to
> become the sort of system that admins would accept in the work place.

All Ubuntu really needs in order to be accepted by admins in the work
place are admins willing to support it. The opposition is, generally,
higher than the admins, in the layer that can replace the admins with
ones that can support whatever they've decided they want to run.

I don't think Ubuntu's problem in gaining adoption in large desktop
deployments is down to how well it copes with an overfull drive. I
think it's the absence of a real competitor to Active Directory, and
the lack of an idiot-friendly mailer like Exchange. 


[0] Ubuntu is patently already "accept[ed] in the workplace" given the
amount of people using it at work.

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