Large snapshots -Windows XP

[robsedor]

I'm running Retrospect 6.5 Pro on Win XP SP1. I'm backing up an entire NTFS drive to another NTFS drive using a "disk" backup. 22gb of data was backed up on the initial backup along with an 8gb snapshot. 1gb of data was backed up the next progressive backup along with another 8gb snapshot. If I continue with a "normal" backup, it appears I will rapidly fill my 80gb backup drive and will need to run a recycle backup.

 

I also backed up a networked Mac running OS 10.2.8. I backed up 12gb of data and the snapshot was only 45 mb. Why is the Win XP snapshot so large and is there any way to minimize its size without compromising the integrity of a full backup?

 

Also, although I specified software compression for both the Mac and Windows backups, the Windows backup had 0% compression while the Mac backup had 11%.

 

Thanks,

 

Robert

[natew]

Hi

 

My first thought is that Retrospect is misreading the size of the snapshot. How much data is actually stored in your disk backup set? How big is the catalog file?

 

If you retrieve a snapshot from the backup set does the catalog file actually grow by 8GB? (if the snapshot really is that big the catalog will be huge)

 

Nate

[robsedor]

My Windows XP catalog file is only 44mb. After retrieving a snapshot, it increased to 66mb. I've done 3 normal backups to my set. The 1st was 22gb, the 2nd was 1gb, and the 3rd was 355mb, yet the size of the backup set is 48gb.

 

Given the size of the backup set it looks like an 8gb snapshot file might be added each time. How do I determine the true size of a specfic snapshot file?

 

Robert

[natew]

Hi

 

That test you ran retrieving snapshots is really the only way. We know for sure that they are only 22MB or so in size now.

 

Just to try to sort this out:

If you get properties on the backup data folder how big does windows say it is? How big does Retrospect say the backup set is?

 

Thanks

 

Nate

[robsedor]

I upgraded 6.5 with the latest patch and ran a recycle backup on my backup set (I was running out of disk space.) Retrospect says it created a 8.1 gb snapshot and backed up 23.6 gb. The catalog file is 44mb. The size of all the files in the backup set on disk is 31.8 gb, so it looks like there is an 8.1 snapshot included in the backup set.

 

What can I do to shrink the size of the snapshot? I'm going to try my next backup without cache files included to see if this helps. (I know Win XP stores tons of well hidden small Internet cache files.)

 

Is it unwise to backup without creating a snapshot?

 

Thanks,

 

Robert

[robsedor]

An update on my last progressive backup from the log: 489.3mb backed up, 8.1gb snapshot created. Catalog is 59mb. My backup set file size is now 40.3gb. It appears that an 8.1gb snapshot is indeed being added and turning off cache file backup had no effect on the snapshot size.

 

Robert

[natew]

Hi

 

The only things that are in a snapshot are your registry and NTFS file permissions for the local machine. Not backing up cache files or other source data will not affect the size of the snapshot.

 

Try this:

Do a backup of a subvolume on your windows disk and see how large the snapshot is.

Also try a backup using the "No files" selector to a file backup set. This should just grab the Registry and snapshot information.

 

Is reformatting the destination drive a possiblity?

How about backing up another windows machine?

 

Thanks

Nate

[robsedor]

I did a backup with "no files" and still had an 8gb snapshot file. I don't have another Windows XP machine.

 

The destination drive was reformatted prior to being used for Retrospect backups.

 

Robert

[natew]

Hi

 

Sorry but I have one more question:

 

Do a no files backup to a brand new "file" backup set. Make sure this backup set is saved on your internal drive. Then do the same thing to a backup set saved on the external drive. After the backups are done compare the size of both file backup sets.

 

Thanks

Nate