Why is it necessary to conduct a full backup prior to performing incremental backups?

Answer 1

"Incremental" means "stuff that's changed since..." so, you have to have something to which "since..." refers! So, for example, you need to have a full backup at January 1, 1751, then "incremental" backups after that, to say, "all files that were changed since January 1, 1751".

An "incremental" backup is just a "shortcut" for doing part of a full backup! You oughta do a full backup now and then, to give yerself a new "since..." just to save yourself some grief, just in case. Watch:

That way, if yer system gets run over by a semi, you'll be able to restore the whole blamed thing, WITHOUT having to do a FULL backup each time, by restoring the FULL backup (the most recent one) then every INCREMENTAL backup since then. That'll bring it up to date.

So, if you did a FULL on 1/1/1751 and INCREMENTALs since then, you'd have a bunch of INCREMENTALs to use!

But, if you did another FULL on 1/1/1951 and INCREMENTALs since then, it'd be a bit fewer, and a restore might take a little less time and less grief, right?

Answer 2

An incremental backup will only save things that have changed since the last backup.

Answer 3

Because the incremental are the updates that occurred since your last full backup. You want your full backups to be up to date since they are the base for all of the backups.

Answer 4

An incremental backup is based on the original full backup; it compares files and looks for things that are different and backs them up. So in order to have something to compare to...

Answer 5

Because it wouldn't work without one! How can you possibly do an incremental backup without having a base to start from?

Answer 6

i think full back up will stand as a beginning reference of incremental back up