iOS 6.1 and Exchange 2010 apid growth in transaction logs, CPU use, and memory consumption KB2814847

Finally Microsoft published article about problems with iOS 6.1 and Microsoft Exchange Server.

When user with mobile devices with iOS 6.1 syncs mailbox Microsoft Exchange Server resources are consumed, transaction logs growth becomes excessive, memory and CPU use may increase significantly,a nd server performance is affected.

You can read about it here:

Rapid growth in transaction logs, CPU use, and memory consumption in Exchange Server 2010 when a user syncs a mailbox by using an iOS 6.1-based device

Right now, Apple and Microsoft are investigating this issue. When they find any fix, it will be published as soon as it will becomes available.

If you have such problems in your Exchange environment you should open case with Apple Support.

Now Microsoft recommend only Workarounds:

The first and the most important is: do not process Calendar items such as meeting requests on iOS 6.1 devices.

If problem still exist then you can use following methods to work around the issue:

Method 1: Remove and re-create the device partnership

To do this, follow these steps:

1. On the iOS 6 device, instruct the user to remove the Exchange account.
2. On a system that is running the Exchange Management Shell, the Exchange Server administrator can run the Remove-ActiveSyncDevice cmdlet to remove the device on the server-side. See the Remove-ActiveSyncDevice topic in Microsoft TechNet online.
3. Wait 30 minutes, and then instruct the user to add the Exchange account to the device. Advise users not to process Calendar items on the device.

Method 2: Create a custom throttling policy for iOS 6.1 users

To do this, follow these steps:

1. The Exchange Server administrator can use Log Parser Studio to identify iOS 6.1 users in the organization. For more information, see the Log Parser Studio details in the “More Information section.
2. Create a custom throttling policy to apply to the iOS 6.1 users. For more information about how to create and apply a custom throttling policy, see theNew-ThrottlingPolicy topic in TechNet online.Apply the following values by using a range of 10 to 30, based on organizational needs and testing:
   • EASPercentTimeInCAS
   • EASPercentTimeInMailboxRPC
   • EASPercentTimeInAD
3. Apply this throttling policy to the iOS 6.1 users who were identified in step 1. Use the Set-ThrottlingPolicyAssociation topic from TechNet online.
4. Notify users that they may receive the “Cannot Get Mail error that is noted in the “Symptoms” section if they try to act on Calendar items.Note The throttling policy will reduce the effect of the issue on server resources. However, users who receive the error should immediately restart their devices and stop additional processing of Calendar items.

Method 3: Block iOS 6.1 users

1. Use New-ActiveSyncDeviceAccessRule like we mention about it in post:
   Devices with iOS 6.1 cause Exchange excessive transaction log growth