I have a large photo collection which I make a point of backing up whenever I add new photos to the collection. I use Retrospect, an excellent backup program that I have used for many years, and I was backing up initially to CDs and for the last few years DVD+R. I started doing backups about 10 years ago so I had more than 600 disks in the backup collection. I considered it a worthwhile safeguard as I have lost photos in the past for various reasons.
I was doing a backup a few days ago and got tired of of the speed of DVDs which is slow at best to write. I decided to move the backup and associated archives onto a large external hard drive (1.5TB) which I purchased for about $120 CAD. I started by making a backup of the current collection which took about 24 hours including verification. It’s a large collection, did I mention that?
I then started copying the backup archives using Retrospect which basically involved reading all the DVDs I had burned and copying the data to the new drive. It has been a fun weekend of shuffling disks in and out of readers.
I was shocked to find out about 40% of the disks had 1 or more errors on them and some where just plain unreadable. I made a point of verifying all the disks as I wrote them since I’ve been burned in the past.
I had made a point of buying quality disks, using a marker that didn’t contain any acid and storing them in sealed disk binders and believing the general consensus that optical media had a shelf life of 100 or more years.
There were some patterns to the failures:
- For a while, I was labelling the disks with stick on labels. Almost without fail, these disks were totally unreadable. Throw out your labelling systems if you have any desire to save your disks for the long term.
- Printable disks that I had printed on were the next most frequent to exhibit failures.
- Disks that were written more than 5 years ago also seem to failed on a regular basis.
In case you were wondering, I tried reading the disks on 3 different DVD drives. An old Plextor model was the best at reading most of the disks. NEC drives worked about 70% of the time and an old Panasonic drive was just terrible.
What’s the moral of this story? If you have important data that you want to keep for long periods of time, better check your optical media. I would suggest making a copy of it to a hard drive and putting the drive in a safe place. At least the drives have the ability to do some type of error correction.
I hate to think of what has happened to all those disks that I made of movies and song compilations that I so lovingly labelled.
Hope your experience is better than mine!