0

On Wikipedia in german about Archivbit, I read the following:

Full backup: The full backup backs up all files - regardless of their attributes - and resets the archive attribute.

Differential backup: The differential backup backs up all files that have changed since the last full backup and therefore have a set archive bit. The archive bit is left unchanged.

Incremental backup: Incremental Backup behave differently depending on the implementation in the respective backup program. So it may be that the archive bit is reset or not …..”

It’s really unclear for me. What is the difference between an incremental backup without archive bit reset and a differential backup? At the differential backup part is it really needed to mention the full backup or would it be enough like this:

The differential backup backs up all files that have a set archive bit. The archive bit is left unchanged.

Are these definitions software specific?
Is there a source with clear, accepted definitions of these terms?

Community
  • 1
GergoKiss
  • 9
  • 2
  • Please, [SF] is not about "Explain unclear wikipedia articles to me". Please read the [help]. – Sven Oct 14 '14 at 11:42
  • Offtopic advice: during your daily tasks you find surely simpler or complexer problems. This site welcomes them. But be specific! (F.e. "What is incremental backup in the Vargane&Tsa backup box?" is much better as "What is incremental backup"). – peterh Oct 14 '14 at 13:09
  • To be precise my question was not "What is incremental backup?" but "Is there a standard definition of incremental backup?". Should I move or delete this topic? – GergoKiss Oct 14 '14 at 13:21
  • This question is not well-defined because the archive bit is OS-specific. I can tell you that DOS and AmigaOS have archive bits with opposite meanings, and Unix doesn't have an archive bit at all. For other operating systems I don't know if they behave as one of the three I mentioned or whether there are systems where the archive bit works in a completely different way. – kasperd Oct 14 '14 at 17:16

1 Answers1

6

No. First: there is not always an archive flag, it is a filesystem-specific thing.

For example, in the case of bacula, differential backup means backing up the difference since the last full backup, and incremental backup means backup since the last differential or incremental backups.

There is also a big spectrum of backup software which can do only full backups, and they aren't thrown out on the first window. Probably they are used by people who don't have to pay for the storage they are using.

Most backup software/solution can only do full and incremental backups.

I never heard about a standardized specification in the topic; the terminology is software-specific.

MadHatter
  • 79,770
  • 20
  • 184
  • 232
peterh
  • 4,953
  • 13
  • 30
  • 44
  • OK, still I find it astonishing that I can find countless seemingly standardized definitions of terms that are software specific. For example here (http://en.wikipedia.org/wiki/Incremental_backup) too there’s not a word about the term being software specific. – GergoKiss Oct 14 '14 at 13:05
  • @GergoKiss It is because it wants to be a science, but it isn't. – peterh Oct 14 '14 at 13:08