Slow Mailbox Backups on Exchange 2007

[huddiel71]

We have been running Exchange mailbox backups for the last couple of years using the same setup. However, it's always been very slow. Throughput is approximately 8GB / hr! The mailbox backups are successful but it is now taking about 3 days to back up all our mailboxes. I'd like to speed this up and need help.

I'm wondering if throughput is being throttled by Exchange. I've found this article

http://technet.microsoft.com/en-us/library/cc540454(EXCHG.80).aspx

by Microsoft. It shows how client RPC requests can be throttled across all clients on Exchange. However, I'm reluctant to change a global setting as I'd like to fix this just for the account used by the CommVault iData agent to back up mailboxes. Anyway, I'm not even sure if changing the RPC throttling setting would fix this.

Our setup works as follows. There was no 64bit Exchange CommVault agent available when we set this up, so I picked an existing 32bit server to use as a CDO 'proxy' server. I installed the Exchange Collaboration Data Objects (CDO) components on this server, pointed them to our Exchange mailbox server then installed the CommVault agent on there, using the method documented by CommVault. So backups are done using a CDO 'proxy' server (\\Intranet) installation of the Exchange Mailbox agent.

Here are the details:

Exchange servers: 2 x client access / hub transport servers and two clustered database servers with one cluster group name.
Exchange Version: Exchange 2007, Enterprise Edition, SP1, Rollup 9. On Windows Server 2003, Enterprise Edition, X64, SP2
CommVault: CommVault Simpana v7.0.0 SP3. CommServer, media agent software and all iData agents are on the same SP and version.

--
huddie

 

[ntinlin]

There is still no 64bit agent even for Exchange 2010 and Commvault v8.

My Exchange 2003 mailbox backup seems to average around 3GB an hour so 8GB isn't bad.
We are also doing Exchange 2010 but a) I can't find a relevant log b) I don't have many mailboxes on there as yet.

Remember that for the brick level you are using crappy MAPI which has to access every item individually for you to pull out of the mailbox. Slow! It's probably as much a matter of number of items as it is the mailbox sizes. Our mailboxes are quite small physically but they all have archiving shortcuts in them which bumps up the item count.

A good test may be to take say a 1GB mailbox and do an export to a PST using Outlook and see how long that takes, this is all Commvault is doing really.

I'd also check your performance when doing the backup to see if you are getting any client-backoff but I doubt you will.
The throttling is more of an issue with Blackberry which makes multiple connections to many mailboxes at once.

I don't know if you have a journaling solution but in this day and age there is no real need to do brick level backups (although try telling that to my management)

Neill

p.s. I'd also run the Exchange performance analyzer when doing the backups to see if it notices anything.

 

[huddiel71]

Thanks for your response Neill.

You said "I don't know if you have a journaling solution but in this day and age there is no real need to do brick level backups (although try telling that to my management)."

Surely you need to do be able to restore individual items, so what's the alternative ? What do you mean by a journalling solution ?


--
huddie

"Keep a cool head and always carry a lightbulb.

 

[baddos]

Surely you need to do be able to restore individual items, so what's the alternative ?

You can restore the information store to a backup information store and recover the mailbox if the mailbox was deleted. It can take some time to recover, but your backup window every night is smaller.

If items inside the mailbox were deleted, you can simply use the deleted items recover feature of Outlook or go to whatever archive system you are using.

 

[huddiel71]

Not really adequate. Restoring the complete backup info store then picking out individual mailboxes or items is overkill and would take far too long. Users can recover accidentally deleted items but only for up to two weeks as this is how long they're retained.

I'm looking for an item level restore. Is there no way of throttling for the CommVault service account mailbox in Exchange ?


--
huddie

"Keep a cool head and always carry a lightbulb.

 

[baddos]

You can try setting up additional subclients that backup say mailboxes a-h and i-z or something like that and seeing if that improves performance. In reality though, the larger your exchange deployment gets the less likely you will be doing a full backup of mailboxes. You could even try doing a incremental backup of mailboxes with a weekly full or something too.