Second backup is huge

[trseven]

I'm backing up all files on an iMac DV SE (summer 2000) OS 9.2.2 to the iMac's hard drive or an external hard drive using Retrospect Express 5.0.201. The first backup to either drive is always of a reasonable size based on the amount of data in the iMac files. The second backup however is enormous in comparison, e.g. a first backup on 4/30/02 was 8.4 GB while an incremental backup on 5/1/02 was 13.8 GB. No more that 0.5 GB of new data was added to the iMac in this 24 hour period. I'm using the same approach that I did with Express 4.3. With 4.3, the size of the backup grew with each incremental backup in proportion to the amount of data added since the last backup. A periodic recycle would reduce the size to reflect more accurately the amount of data. (Going back and looking at old data is not important to me.)

 

 

 

Any suggestions for avoiding this huge second backup without a proportional amount of added data?

 

 

 

 

[Guest]

Retrospect uses several matching criteria to compare files that have already been backed up to what is about to be backed up. If one of the following has been changed at all, Retrospect will back up the file again: name, size, type, creator, creation date and time, and modify date and time.

 

 

 

If Retrospect is reporting that it is about to back up files you know have not changed since your last backup, take a closer look at a sample file. Choose a file and start a restore by search for that file. When you get to the final window (you don't actually have to do the restore), click Files Chosen and Get Info (type Command-I) on the most recent version of the file on the backup. Print or take a screenshot of this window.

 

 

 

Now, go to the Configure tab from the Retrospect Directory and click Volumes. Choose the volume the file is on and click Browse. Find the file in question and Get Info on it. Put the two windows side by side and look for even the slightest difference in any of the criteria I listed above.

 

 

 

Many things can cause a change in a file, even if the file has not been accessed by the user. The operating system, as well as applications, are constantly making changes to files. Further, whenever you change time zones in the Date & Time control panel, your creation and modify dates are offset. We have also found an issue in Mac OS 8.1 with HFS+ formatted volumes where changing the Daylight Savings Time setting offsets the creation and modify dates of all files.

 

 

 

There is also an issue where AppleShare might make a time translation when connecting to another machine whose time is off by more than a certain number of minutes. This time translation would also offset the creation and modify dates of all files. I have also seen this happen when upgrading operating systems or doing a complete restore of data with Retrospect.

 

 

 

Unfortunately the only known way around this problem is to do a full backup of your data. I know of no way to force file attributes to regress to the way they were before. Either do a full backup or use this time to introduce new media.

 

 

 

You should also look at the Backup Set configuration window. From the Retrospect Directory click Configure, then Backup Sets. Choose the set and click Configure. Click Members. Are any members marked "Missing?" If so, mark them found again. Retrospect will attempt to recopy any files on a member marked as missing.