Jump to content
Sign in to follow this  
g.bevan

incremental backup not working

Recommended Posts

Retrospect Multi Server for Windows 7.5.508

 

Hi. I have a backup script scheduled to perform a "normal" (full followed by incremental) backup nightly with weekly rotation. Under "matching" options, the first 2 options are selected. I have no AV running on the server or anything else that could alter the modification dates of the files. I'm also not running a verification check. The backup set backs up to tape (Quantum DLT-S4 800/1600). The source data is on the same server as the tape device and Retrospect is backing the data from a local folder.

 

Problem is, Retrospect keeps backing practically all the files on every run (like a full backup every time instead of incremental). I'm filling up tapes at an allarming rate and keep having to recycle the backup set.

 

Has anyone else got this problem, is there a fix or workaround?

 

Thanks. Grahame.

Share this post


Link to post
Share on other sites

Assuming you've already done a normal backup to a tape based backup set named, for example "tape set a".

 

What happens when you open the immediate backup GUI, choose the same source and destination ("tape set a") as the backup script, then press the preview button?

 

How many gigabytes does it indicate it will backup?

Which files is it choosing for backup?

Here we would expect it to mark only a subset of the files for backup. Is it really selecting 100% of the data?

 

Just to clarify, are you aware that backups must be performed to the same tape (or tape set) for the matching to occur. It cannot match across sets. Given the size of your tapes are 800GB? I assume the whole server should fit onto 1 tape?

 

Can you please clarify "weekly rotation"? Are you switching tapes within the same set, switching sets, or which?

 

Possible explanations:

1. The server is an exchange server, with about 90% of the data consisting of information store. The information store gets backed up in full each time.

 

2. The server is a SQL server, with about 90% of the data consisting of SQL database files. The SQL databases get backed up in full each time.

Share this post


Link to post
Share on other sites

Hi. Thanks for the reply - interesting test! the preview button identifies about 890000 files, 1154Gb with 74000 files, 128Gb to back up. Yet in the logs for the scripted backup (same settings) it's trying to back up about 400000 files, 700Gb.

 

The backups are to the same tape set. I have 2 sets (backup set A and backup set B) set A is in for a week, then backup set B is in for a week etc. The script was based on the weekly rotation model from the easyscript wizard.

 

The server is a simple file server (neither SQL or Exchange).

 

Can't understand the big difference between the previewed manual backup and the scripted...

 

Any other ideas from this extra detail?

 

Thanks again. Grahame.

Share this post


Link to post
Share on other sites
Can't understand the big difference between the previewed manual backup and the scripted...

 

Any other ideas from this extra detail?

Not enough facts provided. Are you using the same selectors both times?

 

Russ

Share this post


Link to post
Share on other sites
the preview button identifies about 890000 files, 1154Gb with 74000 files, 128Gb to back up. Yet in the logs for the scripted backup (same settings) it's trying to back up about 400000 files, 700Gb.

This is a bit inconsistent from your original post, which said:

 

Problem is, Retrospect keeps backing [color:red]practically all the files[/color] on every run (like a full backup every time instead of incremental).

Is the problem that the volume being backed up is greater than expected?

 

The backups are to the same tape set. I have 2 sets (backup set A and backup set B) set A is in for a week, then backup set B is in for a week etc.

 

...

 

Can't understand the big difference between the previewed manual backup and the scripted...

Have you tried this same test immediately after a scripted backup? (i.e., do a preview, note the number of files, followed by another scripted backup).

 

It may just be that the manual preview is (correctly) not showing files that the scripted backup just backed up.

 

Russ

Share this post


Link to post
Share on other sites

"weekly rotation model from the easyscript wizard"

 

I vaguely remember this, but can't find any reference in the documentation. Can you please screenshot the script window so that it shows the schedule?

 

I'm suspecting that the easyscript wizard created schedule includes more Recycle backups than you may be expecting. Keep in mind that a Recycle backup fully wipes all tapes associated with that set and starts backups from scratch, backing up 100% (everything in full).

 

Is it like this?

 

Mon - recycle (wipes tape and does everything)

Tue - normal (only new stuff since monday)

Wed - normal (only new stuff since tuesday)

Thu - normal etc

Fri - normal

Sat - normal

Sun - normal

 

How many tapes do you have in each set? 2?

Share this post


Link to post
Share on other sites

Hi.

 

There are no recycle backups in the script. At the moment, it's showing:

 

  • Normal Backup to Backup Set B
    Every other week on SMTWT.., starting 06/05/2008 at 22:00
     
    Normal Backup to Backup Set A
    Every other week on Friday.., starting 09/05/2008 at 22:00
     
    Normal Backup to Backup Set A
    Every other week on SMTWT.., starting 11/05/2008 at 22:00
     
    Normal Backup to Backup Set B
    Every other week on Friday.., starting 16/05/2008 at 22:00

However, I have remembered a Retrospect bug (limitation) from years ago regarding the maximum number of files that could be scanned, so I've broken down my backup into smaller subfolders rather than the whole parent folder. I'm going to give that a try and see if it works...

Share this post


Link to post
Share on other sites
However, I have remembered a Retrospect bug (limitation) from years ago regarding the maximum number of files that could be scanned, so I've broken down my backup into smaller subfolders rather than the whole parent folder. I'm going to give that a try and see if it works...

I don't believe that this would produce the issue that you have described.

 

Once again I ask:

 

Have you tried this same test immediately after a scripted backup? (i.e., do a preview, note the number of files, followed by another scripted backup).

 

It may just be that the manual preview is (correctly) not showing files that the scripted backup just backed up.

Russ

 

Share this post


Link to post
Share on other sites

Problem Solved!

 

As I suspected, the problem seemed to be related to the number of files scanned as a single source for the backup.

 

In the script, I modified the source from the single top level folder to the 5 or 6 subfolders beneath. So instead of the backup script scanning 800000+ files in a single operation, it now scans approx 160000 files per subfolder.

 

I've run the script a few times now, and each incremental backup is now only backing up approx 12GB / day compared to the 700GB previously.

 

Regards - Grahame.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×