Microsoft Exchange 2010 and replications, backups

[martin_nz]

Hello

I have noticed that over the past couple of weekends my Microsoft Exchange 2010 replication job and backup jobs have increased in the amount of data that is changing and is, therefore, transferred. Normally my replication jobs take less than 10 minutes for an incremental but i notice that the first few jobs on Sunday mornings are taking nearly an hour to run (my replications run from 6am till 7pm 7 days a week) and then they come right and go back to the expected amount of data to be transferred and taking 10 minutes or so for the replication job to run. There is obviously something running on the Exchange server before or during the replication jobs that is causing it to increase in the amount of data to be transferred. Likewise, the backup jobs i have running to two separate places also increase in time.

I've checked the system and application logs on the Exchange 2010 server and theres nothing unusual there.

Has anyone encountered something similar to this?

[Shestakov]

Hello Martin,
Among possible reasons are weekly defragmentation/deduplication processes, antivirus scanning or some weekly Exchange activity which can cause additional changes in data blocks, meaning bigger backup/replication size.
Do you have any of the described activities?
Thanks!

[martin_nz]

I do have a scheduled antivirus scan that kicks off on Sunday morning at 2:30am. Would this be enough to change the data blocks? I don't have any weekly defrag or dedup processes in place and I only have the default Exchange activities running.

[veremin]

Just for the testing purpose you might want to disable the said scan temporarily and see whether it makes a difference. Thanks.

[Shestakov]

Martin, yes, that can be the reason. Since Veeam B&R is an image-based backup solution, it works with blocks, so a change of a file`s timestamp causes copying of the whole block.
What backup method do you use for the backup job, do you make active full backups?
Thanks.

[martin_nz]

I don't use active full backups for my original backup job and I use reverse incremental backup jobs as this goes to tape.

[martin_nz]

I have disabled my scanning job to see how it goes

[itlv2015]

I'm curious if disabling the AV fixes this issue - If AV is the root cause you could always schedule your full scans right before your full backup every month.

[veremin]

Yep, it's not specific to AV, we typically recommend to schedule regular activity that produces a lot of changed blocks to take place right before active full backup.

And if the OP confirms the AV is a root cause, the natural choice will be to schedule it before full backup.

Thanks.

[martin_nz]

What do you mean by active full backup?

[veremin]

I was talking about backup job that has periodic active full backup scheduled. Thanks.

[martin_nz]

Hi All
AN update on this issue - I am still having the long replication time on Sunday mornings even after disabling AV scanning.

Any other ideas?

[veremin]

You might want to open a ticket with our support team and let them identify whether some regular side activities or just Exchange tasks contribute to the increased amount of replication data. Thanks.