Hi Jose,
Regarding your first option about archive/purge for attachments, you cannot archive/purge attachments without archiving tickets. So you would not lose attachments that are on existing tickets. Rather when you purge tickets, their attachments go with it. Now, to address your space issue, you do have a few options. First, is this a physical or virtual machine? If its a virtual machine, your admin team should just add another large drive to the virtual machine, and you can move the attachments there. Service Desk now also allows for the use of a UNC share to store attachments as well, so that is also an option. Now regardless of where you decide to move the physical attachment files, you would just need to update the repository itself to point it to the new directory or share where the attachments were moved. The way attachments are stored in SDM is this: There is an attachments table which stores attachments, their file name, location (which repository) and gives them an ID. Then there is an attachment LREL table which links attachments to tickets for which they belong to. Those relationships will not change, so there wont be an issue with the attachments being associated to tickets. Its the repository itself that points to where the files are physically located, so once thats changed, there wont be a problem.
I hope this helps a bit.
Jon I.