Large Incrementals??

[2MuchNFO]

Hi all,
Rather strange issue which may or may not be a problem.

I’ve been bought in at a late stage to ensure that some Progress databases are backed up regularly.

I’ve little previous experience of Progress Databases in general, and this database in particular, but having set this up previously for another system I’ve used PROBKUP to perform a couple of FULL ONLINE backups outside office hours, and some incrementals (actually I use the -io switch with a value of 4 to make them differentials) during office hours.

The full backups are around 1.7GB.

However, the incremental backups are always around the same size of 1.4 GB, even if I remove the IO switch from the command and run one directly after a previous run.

The data SHOULD be fairly static I would have thought (nobody has been able to suggest otherwise)

The command I use for the FULL backup is…

PROBKUP ONLINE (db name and location) (.bak name and location) –com

Then for each of 4 Incrementals I use…

PROBKUP ONLINE (db name and location) INCREMENTAL (.bak name and location) –io 4 –com

In theory very few changes should be taking place between each backup so I’m surprised that the incrementals are so large. Especially as this is the case for the LIVE and TEST versions of the same database.

Can anyone suggest a reason for this or anything I can check out?
Progress version 9.1C IIRC

Many thanks

Graeme

 

[Casper]

First of all I never use incremental backups so I never experienced anything of this, but -io 4 suggests you can loose 4 incremental backups. It's a rather large overlap.
But anyway. Does this file keep this big after you made 5 or 6 incremental backups? Because the fifth incremental backup you take should only contain the changes between the first and the fifth incremental backup (ergo the real changes made to the database).

Regards,

Casper.

 

[2MuchNFO]

Thanks Casper,

the reason for the -io 4 is to reduce the hassle in the case of a restore.

i.e. We would only ever need the morning's full backup and the most recent incremental to restore.

A new FULL backup runs every Morning and another at night. Only 4 incrementals run during the day so we never get to the stage where we need more than one incremental (the latest) to restore.

Graeme

 

[TomBascom]

IMHO after imaging is a much better solution to this problem.

 

[2MuchNFO]

Thank you. Sadly my knowledge of such things is pretty much non-existent (like the DB backups before I took a look!) Can you point me in the right direction?

If I ignore Progress I would expect the Incrementals (in this case) to gradually increase in size from very small to fairly small, but they just start off large as if most of the data has changed.

Unfortunately I’m not able to ascertain if something is happening to the data (by design) that keeps it changing and therefore gives large incrementals. :-(