Same size of full and differential backups of ntfs compressed folder - Backup Exec 2010

[bschlak]

Hi everybody,

I hope someone can help me with a solution on the following problem:

We have a Backup Exec 2010 Media Server (with all updates - Feb 2011) installed on a Win Server 2k3 (x86). On the same server there is a big folder (350 GB) which is backed up full every 4 weeks and differential monday - friday. Three weeks ago I activated the NTFS compression in this folder to save capacity (~50 GB) on the fileserver. The differential backup still worked (max. 12 GB - after 27 days). Last weekend the full backup was scheduled again and completed successfully. Since then the differential backups are as big as the full backup (350 GB a day). Now I'm running out of space on my backup media. Both - full and differential backup - are working on the archive bit.

Is there a setting I didn't set correctly or doesn't Backup Exec 2010 support a full/differential backup schedules on NTFS compressed files and folders.

Thanking you in anticipation,
bschlak

[RahulG]

Instead of doing differential you can try incremental backup . Diffrerential backup would backup changes from the last full and incremental just backup the changes from last full or incremental backup. Size of the differential backup would keep on increasing

[bschlak]

Thanks, RahulG, for the fast reply.

Unfortunately this wasn't a solution. I configured an incremental backup and performed a test run. The result was the same, the backup size would be about 350 GB.

[AmolB]

What backup method you are using, archive bit or modified time ?

[bschlak]

We're using the archive bit on full and differential/incremental backup.

[AmolB]

You have already mentioned about the archive bit backup method, my bad!!! Could you

please also let us know where are the backups targeted (tape or disk)

[bschlak]

The backups are written to disk. The "disk" is a simple NAS.

[Colin_Weaver]

So if you look at the file attributes after the full backup has completed (on a random selection of files - what are the archive bits set to?

Also I believe there have been issues in the past with Incrementals or differential backups bing unable to correctly reset archive bits over share level access so is this really a NAS or is it operating as SAN storage (possibly over iSCSI) meaning the disks appears as local drives instead of as shares? Reason for needing to query this is if you had the share acces issues I would not have expected it to work even before you added compression.

[bschlak]

The archive bit is set for every single file I looked at. If I am right, this explains why Backup Exec makes a backup of every file even on differential/incremental backup. They were not set back on full backup. But I have absolutely no idea how this could happen; I looked at other (smaller) compressed folder we also backup with this procedure - there it works correctly...

It's a real NAS we are talking about; it's a 4 disk storage with a fixed IP connected to our local network (no iSCSI, etc.) and the folders on the NAS are shared and connected via full UNC paths to our Backup Exec Media Server.

Shall I delete and recreate the backup jobs or is there another way. As I can see now, there will be another 360 GB backup this night...

[bschlak · Accepted solution]

Hi,

I started the full backup again and made a differential last night. Now it works fine; I've no idea why the backup didn't work properly last weekend.

Anyway, my backups are working properly again and this problem is solved!

Thanks for your help,
bschlak