I had the problem about 6 tears ago. I had a folder for every single job (including service calls) that my company had done for 26+ years and it look up alot of room.
I bought a couple of good scanners, hired an extra girl, and had them scan every job into a data-base with notes. All of that fit on a couple of DVDs. I made a copy to put in that safe deposit box @ the bank, and a copy to keep off-site, and we have an office copy. With software I can now retrieve a job by the customer name, address, or any other keyword.
It's a beautiful and efficient system for record keeping.
Now came the hard part. I actually took all of those file boxes of records to the local landfill. That almost killed me but I did it.
Now we scan every job into the database and only keep the hard copy for about 3 years.
AHHHH