Do you have a way to determine the number of backups you should keep of a bit of data?

May 19, 2011
I have two backup drives, each with an 'everything' backup set of my data that I wouldn't want to lose. It's not quite everything but I wouldn't be crying about what was missing should the worst happen.
I also have a drive for storing as many backup sets as possible of particularly important bits of data such as my main documents folder, Firefox and Thunderbird profiles, etc., and each backup set of each bit of data is datestamped in the filename.

When catching up with my backups today, I decided to remove a particular bit of data from my 'multi backup set': Due to my line of work I store locally the manuals for say motherboards I've used. While I don't expect these nor their parent companies to just disappear from the Internet at any point soon, companies can make boneheaded decisions and companies do sometimes go under, however I thought that having three copies of that particular bit of data was more than enough and since I don't go deleting or editing data in that folder very much if ever, the likelihood of corruption is minimal. However I obviously decided at some point that my 'manuals' folder was important enough to warrant the extra protection (perhaps because at the time I decided it was a fair bit smaller than it is now?), so I'm wondering if I'm looking at this situation at enough angles to make a sound decision.

So my question is basically how do you decide that a particular bit of data is important enough to make the grade of storing lots more backup sets, do you have a rule of thumb that you go by?


Diamond Member
Aug 11, 2001
Value of data (in money/work-hours or irreplaceability/sentimentality) vs cost to store X # of copies, including consideration of the effort needed to maintain X # of backup sets.

As far as motherboard info/manuals, and drivers (that I store by chipset instead of per motherboard so I don't have multiple copies of each in the parent directory), those along with any other compute-related hardware pics/docs/drivers/etc are stored in 3 locations, two on a fileserver on different drives, and one on an offline external HDD used to backup the fileserver. I'd guess that's around 20GB x 3.

I'll probably soon start storing all that on a USB flash drive too. I already have all that for the motherboards and other hardware I still own and use, on a flash drive. Oh wait, I probably have a 4th copy on a HDD I pulled out of the fileserver when I swapped in a newer larger one a few years back, but who knows if that HDD still works after sitting around all this time.

I never assume that at some later date I'll be able to get something off the internet even though that has been mostly true, with exceptions like Abit going under when my main rig had an Abit board in it, but they kept their site up for what, 3 years after that?
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Oct 9, 1999
3 copies with one being cold and offsite should do it. I keep my offiste backups at my bros house, and have one copy backed up local as well.
Oct 20, 2003
3 copies with one being cold and offsite should do it. I keep my offiste backups at my bros house, and have one copy backed up local as well.

Old IT saying: "If your data doesn't in at least 3 places, it doesn't exist at all"