Research how the check for upgrades could require less RAM
It might be that the initial check for available memory (in the shell wrapper) uses overly conservative settings. Otherwise, porting the whole things from Moose to Moo (doable on Wheezy) or Moops (doable on Jessie, with a couple backports) might help.
Related issues
- Related to #6876
- Related to #10115 (closed)
Original created by @intrigeri on 6877 (Redmine)