If your company is using the Microsoft Online Services Directory Synchronization tool and you have a very large Active Directory directory service or very large distribution groups, directory synchronization may fail with the “Maximum Request Length Exceeded” error message in the Event Viewer.
User accounts, contacts, and groups are Active Directory objects. The Microsoft Online Services Directory Synchronization tool synchronizes Active Directory objects in batches. The default number of objects to include in one batch is 20 and the size of each batch after compression must be 4 megabytes or fewer.
When synchronizing groups, the complete group list is sent whenever a member is added or removed. If your groups have many members, there may not be room in a particular batch for all 20 objects. If you receive the “Maximum Request Length Exceeded” error message, you should reduce the number of objects in a batch to optimize directory synchronization for your situation.
The number of objects in a batch can be set by a registry key. To edit this registry key:
1. On the directory synchronization computer, run RegEdit.exe and navigate to HKEY LOCAL MACHINE\Software\Microsoft\MSOLCoexistence.
2. Add a new DWORD value named “ExportBatchSize.”
3. Set the value to less than 20 and test synchronization again.
4. Continue reducing the value until synchronization succeeds.
For information about editing the registry, see Windows registry information for advanced users.
When are you going to bring out a 2008 (hopefully R2) compatible version of the Sync Tool? It'd be great if it also had AMD64 bit compatability as well. Or do you have any work arounds for getting it running on a 2008 R2 AMD64 machine?
Hi Jeremy, The Directory Synchronization tool already supports Server 2008, with the latest service packs.
The Directory Synchronization tool is based on technology that is currently available in 32 bit only, and there are no plans to change that any time soon. Your best bet for running on a 64 bit machine at this time, is to run Directory Synchronization in a 32 bit virtual machine.
I've also pasted this reply to your other post of the same question.
I hope this helps,
It would be great if the tool had the ability to perform a sync now, rather than running through the entire wizard. Also, the ability to sync user passwords from AD to Exchange Online would be a huge benefit.
Thanks Kevin. I believe that there is a way to sync now, without running the tool. I'll find out and let you know.
Hello again Kevin. I thought I remembered this. We have published a Help article on how to force synchronization from the command line using a PowerShell cmdlet.
The article is published at http://www.microsoft.com/online/help/en-us/bpos/index.html?page=html%2F7cec3db1-c48b-4141-b4ec-561588a9a432.htm.