Comment 0 for bug 1785096

Revision history for this message
Brian Murray (brian-murray) wrote : dist-upgrader does not clean up downloaded debs

During the release upgrade process packages for the new release are downloaded to the apt configuration "Dir::Cache::archives" (usually /var/cache/apt/archives/), but those are not removed from disk until some time later. With the dist-upgrader growing support for transitioning from debian packages to snaps for some software it's possible that there may not be enough free space on disk (as the upgrader doesn't currently calculate the space need which is bug 1783597) to support installing the snaps. Subsequently, it'd be good to remove the debs from disk after the upgrade has completed since they are likely on /var which is where the snaps will need space.

[Test Case]
1) Run 'du -sh /var/cache/apt/archives'
2) Upgrade from Ubuntu 16.04 to Ubuntu 18.04
3) Run 'du -sh /var/cache/apt/archives'
4) Observe that /var/cache/apt/archives is taking up more space than it id.

With the version of the dist-upgrader in -proposed /var/cache/apt/archives should be nearly empty some debs may be left because they are left over from regular updates in Ubuntu 16.04 and were not part of the release upgrade process.

[Regression Potential]
It's possible that the debs are removed too early and if there were a failure to upgrade it'd be hard to recover from. One way to test this would be to use the apt-clone file from 1766890 which would create an upgrade failure.