Exchange Mailboxes Backup Performance Issue

[Sandeep_Sawant]

Hi All,

I am facing backup performance problem in Netbackup 6.0 mp5 for Exchange mailboxes it takes approximately 30-35 min(or more than that) to take a backup of 1.4 gb Mailbox (at a backup speed of 200 - 300 kbps) on Backup LAN. And also I have created a 1Gbps backup LAN for taking Exchange & File server Backup. Below is my setup detail

Netbackup Server:

                        Windows 2003 ENT. Server with service pack1.

                        Netbackup 6.0 with MP5

                        Public LAN à (172.26.200.0) network

                        Backup LAN à  (172.26.211.0) network

Exchange Server:

                        Windows 2003 ENT. Server with service pack1

                        Exchange 2003 with service pack 2.

                        Netbackup 6.0 Client Agent with MP5.

                        Public LAN à (172.26.200.0) network

                        Backup LAN à  (172.26.211.0) network

Note:  It takes approx. 5 hrs to backup Exchange Information store of 257 GB on Public LAN

regards,

Sandeep

[Jonathan_Martin]

Are you thinking there is an issue between your backup and public lans?  If so, you need to compare apples to apples.  Backup the entire Information Store via the Public and then the Backup lans and comapre the speeds.  You can't compare a full backup on the Public interface to a mailbox backup on the Backup interface.  Its pretty well established that Full Database backups are many time sfaster than mailbox backups.  Thats got more to do with how the backups occur than what interfaces they are using.  The full mailbox backup backups up the physical .edb files and then the log files.  The mailbox backup has to make Mapi calls to the Information Store, a much more cumbersome process (hence the slower performance.)  Given you are running Exchange 2003 which gives you Recovery Storage Groups, why not just do full backups and then restore individual SGs as needed to get to mailboxes?

-Jonathan

[kimleong]

Hello Sandeep,

Can you post the output of your Exchange IS backup policy (remove your hostnames if it's confidential)? Are you using multi stream? I've seen vast improvements by specifying 4 storage groups in the backup selection instead of letting NBU/Exchange backup one by one serially. I can easily achieve ~120GB/hour Exchange backups over a Gigabit LAN.

Have you done a simple FTP test between the Exchange client and NBU master server to ensure that it is able to provide you the bandwidth? (ftp test of a large 1-2gb file should be > 50MB/s). What about the tape drives? What kind of tape drives are you using?

Try and do a FTP test of a DVD ISO image (that is easily 4GB) between the master server/exchange client and see what speeds you get. How did you configure to force NBU to use backup LAN and how certain are you that traffic is going via the backup LAN?

Jonathan is right for single mailbox backups. Those type of backups are painfully slow due to the Exchange architecture for single mailbox backup. The recommended way (which is also listed in MS KB article) is to backup the IS, and then restore to Recovery Storage Group and extract out the mailboxes required using the exmerge utility. Single mailbox backups should be used only for VVIPs, perhaps no more than 20-50 very critical mailboxes (this is my personal opinion). The rest should recover via RSG.

The best you can do is tune up the multi stream and tell NBU to backup 4-8 mailboxes at a time instead of 1 by 1.

Message Edited by kimleong on 09-03-2007 05:37 PM

[Stumpr2]

Hello Sandeep,

You were given some excellent suggestions and followup questions. Were you able to resolve your problem? If yes, then what was the solution?

[DavidParker]

" ...it takes approximately 30-35 min(or more than that) to take a backup of 1.4 gb Mailbox (at a backup speed of 200 - 300 kbps) ... "

That sounds about right for mailbox backup speeds from what I've seen with Exchange backups ...
Doing mailboxes and Information Stores backups is kind of redundant now that you can use the Recovery Store to process whatever type of mail restores are necessary ...


Message Edited by David Parker on 11-09-2007 12:12 PM

[Omar_Villa]

Hi Sandeep,

      I use to backup a 150GB Exchange DB and was taking 8 hours to end, that was because the kind of drives where performing the backup, we change that from DLT IV to LTO and was reduce to 2-3 hours, so check that probably the networks is not your botleneck, also I will recomend you to check the Backup and Peformance Tunning document, so you will touch all the posible points who are making your backups to go slow.

Hope this helps.

Regards