Archive bit, how and why?

binarysoulbinarysoul Member Posts: 993
My experience with backup is very weak, non-existent.

I'm thrown off by incremental/ differential backups, especially when 'archive bit' is mentioned. I know their definitions, but can someone put it in layman's terms or suggest a software that I can practice?


  • bhcs2014bhcs2014 Member Posts: 103
    The archive bit determines whether or not the file needs to be backed up.

    For full and incremental backups the archive bit of files are "checked". For differential backups they are not checked.

    New files that are created will have unchecked archive bits (They need to be backed up) .When files are changed the archive bit is unchecked (File changed, it needs to be backed up again)

    When a backup job runs the backup job will check each file to see if the archive bit is checked. Ones that are not checked will be backed up (and may be checked depending on the backup type).

    These methods ensure everything is backed up at all times. They also determine how difficult it will be to restore a backup. If a server has been backed up to like 5 different drives (incremental backup) it will not be as easy as it would be to restore a server backed up to only one drive (full backup) or two drives (differential). Advantages of incremental backups are that they will use the least drive space, server resources, and bandwidth.

    For example we do full backups every Sunday and incremental backups every other day.

    That is the basic gist of it. It's not really something you need to practice, just understand the concepts.
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