Backup Maker Archive Bit Settings

I'm trying to figure out the right settings for the differential to backup only the new files.

I think the problem has to do with the settings for the archive bit, either:

"Back up files with set archive bit only" or "Reset archive bit on backed up files." or both or neither

backup — Postimage.org

If it's relevant, I'm backing up to an external SSD. If I want to run a differential from the last full backup, do you know what the archive bit settings should be?

Thanks

386DX said:

I'm trying to figure out the right settings for the differential to backup only the new files...

I don't use Backup Maker, I have written a batch file of my own to do Full and Incremental backups of my user data. I makes extensive use of the Archive bit to do this.

To do a Full backup, tick just the box for 'Reset archive bit on backed up files'. This will back up everything, resetting all the archive bits. Any file that is modified after this will have its archive bit set, so it is easily identified.

There are two types of backups you could do after this, an Incremental or a Differential. The difference is that for a Differential all files changed since the last Full will be backed up, meaning that a subsequent Differential will contain the same files as the previous one, plus any new changes. A complete backup set is therefore the Full plus its latest Differential.

For an Incremental only changes since the last backup (Full or Incremental) will be backed up. Each Incremental will only include files that have changed since the last one. A complete backup set is the Full plus all subsequent Incrementals.

Once you have made a Full and have reset all archive bits, for the next backup to be a Differential, just tick 'Back up files with archive bit set only'.

For the next backup to be an Incremental, tick both 'Back up files with archive bit set only' and 'Reset archive bit on backed up files'.

Decide if you want to make Incrementals or Differentials and stick to it, at least until the next Full. If you mix the two you'll get a headache trying to work out which you need to keep for a complete backup set.

Thanks, Bree. This is the clearest explanation I've seen on backup. I'll try it.

Whether I check one box, the other, neither or both, it always runs a full backup. I'll reinstall, unless I'm not getting the logic.

386DX said:

Whether I check one box, the other, neither or both, it always runs a full backup...

For your first backup the archive bit will be set on all the files, so everything should get backed up.


Provided the first backup cleared all the archive bits, it's the next backup where you can choose if you want to just back up files with their archive bit set and clear them.



To check if it is working as expected you can look at the file attributes with Windows Explorer in its Details view, but not by default. You have to right-click on the row of column names (Name, Date, Type, etc.). Select 'More..' in the menu then tick the box for Attributes. An 'A' in the column means the archive attribute is set.

Thanks again Bree for helping me work through this. I’m having trouble understanding the logic and syntax of the archive bit. For me it’s a double negative kind of thing. :) I think I need to understand how the two states of the archive bit are defined. When it's "set," does that it will be backed up again? To me, the syntax says it's archived now, no need to back it up. Do I have the entire logic wrong?

If the archive bit is "set," does that mean it's saying hey, back me up? So then those files would be backed up whether we call it a Full or Diff, correct?

Does "Resetting archive bit on backed up file" mean once a file is backed up, it re-raises its hand to say back me up again? If that's true, then the first BU should have neither checked, correct? I checked neither, and all files are then backed up, so far so good. See screenshot. Windows Explorer attribute is A.

Then, for the first Diff BU, I checked the top box only (“Back up files with set archive bit only”), but all files are backed up. See screenshot. Windows Explorer attribute is A.

So using their logic with check boxes, how do I run a diff to back up only the files that have been changed since the last full backup?

Thanks again.

386DX said:

If the archive bit is "set," does that mean it's saying hey, back me up? So then those files would be backed up whether we call it a Full or Diff, correct?

Correct. The Archive bit means the file needs backing up. When you have cleared the archive bit, anything that modifies or edits the file will set the archive bit again. Think of the archive bit as saying 'this file has been modified'.

Does "Resetting archive bit on backed up file" mean once a file is backed up, it re-raises its hand to say back me up again?

No. It means that after the file has been successfully backed up the archive bit will be cleared. If you then only back up files that have the archive bit set, this file won't be backed up until it is modified and gets its archive bit set again.

Thanks, Bree. I'll come back to this asap.

UPDATE: I checked the settings I use for backing up other folders. The settings are the same as for the folder I'm having trouble with (Mary), but the others run a Diff fine...just backing up the changed files. Does this sound like a bug? I reinstalled but same.

386DX said:

...the others run a Diff fine...just backing up the changed files. Does this sound like a bug?

If it works as expected in all folders except this one, it sounds more like another program that uses this Mary folder may be setting the archive bit on all the files.