We have been running webwork for a fairly large installation on 32-bit ubuntu. The number of users has gotten large enough that occasionally we are running out of memory that is limited by the 32-bit operating system. To fix this, I installed the 64-bit version from LiveDVD, archived the courses, moved them to the new 64-bit version, then unarchived them there.
Everything worked like a charm except for the fact that students cannot view their answers that were submitted on the old system becuase they are base64_encoded in the database. The student gets a pink screen with the following error message:
Warning -- there may be something wrong with this question. Please inform your instructor including the warning messages below.
WeBWorK has encountered warnings while processing your request. If this occured when viewing a problem, it was likely caused by an error or ambiguity in that problem. Otherwise, it may indicate a problem with the WeBWorK system itself. If you are a student, report these warnings to your professor to have them corrected. If you are a professor, please consult the warning output below for more information.
problem fetching answers -- possibly left over from base64 days. Not to worry -- press preview or submit and this will go away permanently for this question. Storable binary image v49.97 more recent than I am (v2.7) at ../../lib/Storable.pm (autosplit into ../../lib/auto/Storable/thaw.al) line 415, at /opt/webwork/webwork2/lib/WeBWorK/Utils.pm line 837
So I created a new user on the new system and answered the same question. The answer is indeed in clear text in the database and not base64_encoded.
This is no problem at the end of the semester since we will be starting new courses and the system will work fine, but since we are trying to do this in the middle of the semester to aleviate poor server performance when we reach the memory limit, this becomes a problem. The pink screen with the error message will be trouble enough, not to mention the fact that the student will not be able to view their old answers when using the system to study, etc.
Any ideas on a work around for this?