BE2010 - Backup Times with Differential

[downloadkid]

Afternoon everyone, I'm after some general advice / voices of experience.

I have until recently always done full nightly backups, the window of opportunity was long enough and the tapes big enough.

However that's starting to change so I set 2 schedules;

1. Every Monday perform a full backup

2. Every Tuesday - Friday and Differential

So far it works fine but I am curious I was under the impression that a differential back up would take considerably less time, in this instance it hasn't't.

A full back up  will take around 16.5 hrs at a speed of around 1700MB/min. The incremental takes literally almost as long at a speed of around 397MB/min.

A full back up is around 660Gb the differential so far around 6Gb. I had hoped that in using a differential I could reduce the size of the backup window.

What are your experiences?

thank you

[AmolB]

Incremental backup will backup all files modified since last full or incremental backup, so it will backup

less data and it will take less time. Differential backup will pick up all files modified since last full backup

hence it backups more data and takes more time.

[Ken_Putnam]

A full back up  will take around 16.5 hrs at a speed of around 1700MB/min. The incremental takes literally almost as long at a speed of around 397MB/min.

A full back up is around 660Gb the differential so far around 6Gb

Sonething is seriously wrong somewhere.  There is no way that DIFF that is 1% of a FULL should run at 20% of the throughput of that same FULL

Try re-creating the DIFF job

[pkh]

Are you using the archive bit method?  If so, an incremental backup can take some time because BE has to examine each file in turn to see whether the archive bit is on or off.  This takes time especially if you have a lot of small files.

Try using the modified time and the USN journal, this will cut down time on the search.  If you are switching method, you must take a full backup after the method switch.

[OP]

Hi !

are the devices you're backing up physical or virtual machines?