New upgrade for Apple devices like IPhone or IPad to iOS 6.1 can couse Exchange Admins headache.
With new version of iOS (iOS 6.1) we have new problems, users connecting to Microsoft Exchange mailboxes using mobile devices with iOS 6.1 can generate excessive transaction logs.
This is caused by syncing mail and calendar services, devices with iOS 6.1 seemed to go into a loop and ended up by generating some 50GB of transaction logs.
This situation can be dangerous for Microsoft Exchange server, because when free space for transaction logs will end, then Exchange will dismount mailbox database.
Upgrading Apple devices to new iOS to fast is not recommended.