When disk space is low, apt-get install something
operation (invoked by superuser)
can uses the disk space over the watermark for the ordinary user
(as in ext2 filesystem)
and as a result, when normal user tries to
use the system it finds
the filesystem in which /var/spool/apt is located
having no usable space left.
Often this causes undesirable side effects.

It would be nice if apt can warn this dire condition
before the apt-get install begins.

It is highly desirable that apt-get WARNS
the dire condition to the superuser AFTER
the apt-get install finishes and
the space usable for ordinary user is zero.

I assume that the judgement for the space being "low"
can be user settable, etc. and so might be a
little complex and so I say it would be NICE to
warn the user beforehand and afterward.

However, it is definitely desirable to print warning
if the left over space is ZERO for ordinary user after the install
operation, though.


dpkg --status apt
Package: apt
Status: install ok installed
Priority: optional
Section: admin
Installed-Size: 1984
Maintainer: APT Development Team <deity@lists.debian.org>
Version: 0.5.4
Replaces: libapt-pkg-doc (<< 0.3.7), libapt-pkg-dev (<< 0.3.7)
Provides: libapt-pkg-libc6.2-3-2-3.2
Depends: libc6 (>= 2.2.3-7), libstdc++2.10-glibc2.2
Suggests: dpkg-dev
Description: Advanced front-end for dpkg
 This is Debian's next generation front-end for the dpkg package manager.
 It provides the apt-get utility and APT dselect method that provides a
 simpler, safer way to install and upgrade packages.
 .
 APT features complete installation ordering, multiple source capability
 and several other unique features, see the Users Guide in
 /usr/share/doc/apt/guide.text.gz

s/apt-get install something/any/

This doesn't seem like apt's responsibility.  You could fill the disk just
as easily using tar or dd as with apt (more easily in fact).

In order for apt to warn about this, it would need to have an undesirable
amount of intelligence about the type and configuration of the filesystem.
apt doesn't know anything about filesystems, and there is no reason for it
to learn now.

Matt Zimmerman wrote:

Thank your for taking the time to respond to my wish list posting about
apt behavior.

Your points are well taken, but under linux, I can be a little
careless since I am the sole user of this home PC and
I do need to get  to update packages from time to time.

Anyway, regarding the file space detection,
the most likely culprit would be the usage under
/var/cache/apt. (Ordinary users tend to forget to run
apt-get autoclean from time to time [another warning
candidate...]), and so /var/cache/apt can fill up
over time.)

If we restrict the focus to /var/cache/apt,
won't the detection be a simple matter of running
df -k /var/cache/apt and look at the remaining size?

On my PC, it goes like this.
df -k /var/cache/apt
Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/scsi/host0/bus0/target4/lun0/part6
                       7053444   6151964    543184  92% /

Aga. devfs device name struck...
But we can use -P flag to df.
ishikawa@duron$ df -k -P /var/cache/apt
Filesystem         1024-blocks      Used Available Capacity Mounted on
/dev/scsi/host0/bus0/target4/lun0/part6   7053444   6151980
543168      92% /
ishikawa@duron$ df -k -P /var/cache/apt | tail -1 | awk '{ print $4; }'
543168

The last command is to obtain the remaining capacity.
Yes, I agree that checking the watermark (reserved for user)
is rather difficult, but then simple checking for this
remaining space or checking for the percentage is just fine.
If remaining space is less than 5% warn the user, etc..

Since apt-get is built to show the exact amount of
file space used for installing new package and
seem even to bother caculating the difference between
the space occuped by the current version of the package
and the space occuped by the new version of the existing packages,
a little extra effort to show the remaining file space at the
end of apt-get at the end of the execution won't hurt IMHO
(and the calculation should not be that hard and
users are better off even with a crude estimate based on df output.).

Anyway, thank you for the great package.
I wish more commercial distribution of linux pick up apt-like
package system.





df -k -P /var/cache/apt






df -k /var/cache/apt

This is true, and it is a regrettable side effect of the popularity of the
command-line tool "apt-get".  This tool is not a full-featured frontend to
the package management system, and so does not provide a "friendly"
interface which asks the user about things like cleaning /var/cache/apt.
Ordinary users should probably be using aptitude, or (if they have a taste
for that sort of thing) dselect.