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Exchange DAG Backup Too Slow


I have trouble with my Exchange DAG backup which is too slow to finish. Backup one DB (300GB) can takes two days to finish without GRT enable. With GRT enable, it will worsen the situation. NetBackup version is 7.0.1. We had Exchange 2010 running in HyperV platform. Connection from SAN storage to HyperV server using 1GB iSCSI connection. We have 2 tier backup architecture with Master and Clients only. Details :

MASTER SERVER : Windows 2008

EXCHANGE CLIENT : Windows 2008




How we can improve our backup speed?

4 Replies

Can I assume that you are

Can I assume that you are running the backups to disk as you only mention tape above and GRT backups cannot run to tape?

If so what are you other backup speeds like?

Are you using BUFFER files to tune your backups?

If not then on the Master Server add the following flat files (no extention and they must be upper case as shown):


SIZE_DATA_BUFFERS_DISK with a value of 1048576 in it

NUMBER_DATA_BUFFERS_DISK with a value of 32 in it.

For the tape tuning use

NUMBER_DATA_BUFFERS with a value of 32 in it and if you are using LTO4 or LTO5 also add

SIZE_DATA_BUFFERS with a value of 262144 in it

No need to re-start any services

As long as you are confident that your network is good (full duplex everywhere etc.) then these should help

Information Store backups are generrally very fast so if this tuning still does not help you need to find the bottleneck somewhere else - check out Anti Virus scanning the NetBackup processes or the backup to disk folder

Hope this helps

try to



try to disable database consistency check option from the dag client and re run the backup.

this options being from the host properties - dag clients - exchange

I'm having a similar

I'm having a similar issue...

I have consistency snapshots enabled but isnt the consistency snapshot required for backing up the passive copy?

in the past

l had the same issue and then when l uncheck this options the backup completed in a short time. no l talked with this from the symantec employee and ha said that there werent any problem to taking backup like this.