Subscriber JNC wrote to me to say that he’d been using Acronis True Image for a while and wanted to know about keeping old backups:
I have just completed a total backup via Acronis on my external hard drive.
Is there any reason to save previous total backups?
My external (500) hard drive is over 2/3 full.
I wrote back to JNC to say that I wouldn’t get rid of all of them. I suggested that he keep some recent ones and one or two full backups from the past — including the oldest one he had.
I find that, most of the time, I’m reaching for a backup file or backup image file because my brain messed up, not because of a hardware failure.
It’s too easy to change a file and not realize that we haven’t done the change correctly. We find it out later when we try to use the file, or that part of the file. It might be days, weeks or even months later.
When I find the problem and find my backup image, my first step is to rename the current (bad) version. Then, I restore the old one (the backup copy), and then copy & paste to add whatever data I can from the most recent copy into the "good" older version.
It’s not a new problem. Back in the Lotus 1-2-3 days, I had a data clerk working for me who tried to hide some columns from view (to enable him reformat the screen to include more columns he was using); instead, he accidentally deleted the columns.
He didn’t realize it for about 3 weeks, and he had no backup old enough to have the missing parts of the spreadsheet. He had to go back to the original data to completely re-create the spreadsheet, cell by cell.
Back in the early days of pc’s, my rule of thumb was "You always need one more backup than you have."
When backups are a pain to create, you won’t have enough.
When backups are easy to create, especially with image backup programs like Acronis True Image which can make complete computer backups, differential backups and incremental backups on a scheduled basis, you can make sure that you won’t lose your data.