Backup Question

[UnknownScout]

When using BE 9.1, our daily differential backup's average about 12-15 GB. This seems relatively low, as the exchange databases public and private are around 20GB themselves, plus our ERP software's databases are around 9GB. Then there is the rest of the backup. Shouldn't the total be larger than 12-15GB? It used to be like 50 a night before I was in this department. Any input would be appreciated.

Thanks,
Paul

[Renuka_-]

Hello,

1.A differential backup does not backup everything but only the changed files since the last full backup. So it will evidently be less than a full or the actual total volume.

2. You can In addition check what is being backed up from the backup job log or restore selections.

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this post would be 'assumed answered' and archived."

[UnknownScout]

I know that differential (daily) backups will be less than our full weekly backups which are around 160GB. My question is though shouldn't the daily be larger as the exchange databas changes daily as users receive and delete e-mail. This data comprises nearly 20GB alone not to mention the other files that change. Our backups are only around 15GB a night (average this week so far).

[Renuka_-]

Hello,
Another thing you could try is that verify tha actual volume of data backed up without compression incase you are using compression, software or hardware.

"NOTE : If we do not receive your intimation within two business days,
this post would be 'assumed answered' and archived."

[UnknownScout]

well the volume says that it's using 6.xxx compression, and that there's 15 gigs written and the volujme at 6.xx compression shows 97 gigs of 100 gigs free on the drive using 2.xx gigs., so this isn't really valid...

Maybe if I rephrase it this way. Is exchange a flat file database, and any changes to it forces a whole backup? Or will it only backup changed items sort of like a (relational database)?

Thanks,
Paul

[A_van_der_Boom]

> Maybe if I rephrase it this way. Is exchange a flat
> file database, and any changes to it forces a whole
> backup? Or will it only backup changed items sort of
> like a (relational database)?

Keep in mind that when a user deletes an e-mail from Exchange it is not immediately removed from the Exchange database. This all depends on how you configured the retention time. Exchange has maintenance cycles in which it will clean deleted items/mailboxes. Only after a maintenance cycle has run you will see any change in the size of the database.

When you install the Exchange agent you can, just like a file backup, only backup the email items which are changes/added via a bricklevel backup (Although this is not the preferred backup method of Exchange)

For more information about Exchagne check the Microsoft site.

Regards
A van der Boom

[UnknownScout]

That was some helpful information, and for our daily backups we just do differential - logs on exchange and differential "changed messages" for the mailboxes. The weekly full backups we complete full backups on exchange and the mailboxes. This is why we're not backing the full database up on weeknights? It's only backing up certain records in the database?


Thanks again,
Paul

[Amruta_Purandar]

Hello,

- Please note that Logs backup will be smaller than the database + logs backup.
- Also the mails backup that you are taking is for changed messages only.
Hence this will again be a very small part.

===

However to verify it yet again, try the following
- Spilt the Differential Exchange and normal backups.
- Also split the Full Exchange and normal nackups
- Verify the results.

NOTE : If we do not receive your intimation within two business days, this post would be marked ‘assumed answered’ and would be moved to the ‘answered
threads’ pool.

[Sheetal_Risbood]

As per our previous reply, marking the case as assumed answered and moving it to answered questions pool.