Duplicating on 2 different drives

[John Hinckley]

Hi All,

 

I would like to pick up on a post I made about 3 weeks ago as it has not been resolved, and I'm hoping someone with far more experience than me can help with this.

 

I am using Retrospect 7.5 and duplicating the contents of my hard drive to an external HDD which is USB connected. There is around 400GB of data, most of it static and doesn't change from one week to the next. The first copy took some time as it had to copy the whole 400GB.

 

Subsequent copies are fast as only files which have changed or been created are copied.

 

My problem comes when I want to duplicate the contents of the same drive in my PC to a 2nd external HDD which I then keep off site.

 

After doing this, the following week I go back to the 1st external HDD to update the duplicate, expecting Retrospect to copy/replace just those files which have changed or been created. Instead, it reports ALL files having changed and wants to copy the whole 400GB again from scratch, even though 95% of these files are static and have NOT changed. Retrospect thinks they have.

 

If I re-duplicate the whole lot again, then duplicate to the 2nd HDD, the same happens. Retrospect thinks the whole lot has changed and wants to redo all 400GB.

 

I know Robin Mayoff has explained that the files must have changed for Retrospect to want to copy the whole lot, but honestly, they haven't. Most of them are static files which don't change (like photos, music etc.)

 

Something in Retrospect changes the files on 1 drive which does not match when you try to duplicate to the 2nd drive.

 

I need to use 2 external drives, as one is backed up and kept on site, the other (a week later) is kept off site. Using Retrospect in this way just doesn't work with 2 drives. The drives are identical.

 

Any help on this would be great as I want to keep using Retrospect, but can't keep going on like this.

 

Many thanks.

John :confused2:

[Mayoff]

Retrospect looks at name, size, creation date and time, modify date and time, meta data, permissions and in rare cases the path. In some cases the archive bit is also used. If any of these items change by even 1 second, the file must get copied again.

 

Have you looked at each of these criteria on the source vs the destination for files that are getting recopied?

 

Retrospect can not modify files on the source drive when doing a copy, so any changes that happen to a source file are happening outside of Retrospect.

[John Hinckley]

Thanks Robin,

 

I can't see any difference in the files and I have compared some using Diskcomp and they compare OK.

 

Is there any way to selectively switch off some of the above checks? Its a pity Retrospect can't just check the file using something similar to Diskcomp.

 

Most frustrating as I can only use 1 drive. Copying 400GB over several hours just takes too long every week.

 

John

[Mayoff]

Do you see the same problem when you do a backup instead of a duplicate?

[John Hinckley]

Thanks Robin,

 

I will try a backup and let you know the outcome.

 

Just a thought...I have read through the forum and note that Saberman had a similar problem and reported this as a possible bug in Retrospect??

 

Regards

John

[saberman]

Just a thought...I have read through the forum and note that Saberman had a similar problem and reported this as a possible bug in Retrospect??

 

My problem occurs in trying to duplicate a directory tree across my LAN. If I duplicate the directory tree from one USB drive to another on the same machine the process works as described. Unchanged files are not copied. If I duplicate the directory tree to a USB physically attached to another PC using my LAN then I get the problem. As near as I can tell, the method Retrospect uses to copy across a network sets the last modified date to the time of the copy -- not the time on the original file. I think this causes the extra copies. I cannot be sure without access to the Retrospect source.