Office 365 introduced throttling on user connections, which impacts migration performance. The throttling is a per-user limitation that reduces capabilities after more than two connections by a single user (including the <MigrationAdmin> user). With previous versions of Exchange Online, migration throughput rates of 3-5GB/hr per machine were common. But Office 365 throttling reduces typical throughputs to 500MB/hr or less per machine.
Most Office 365 projects therefore require multiple migration machines (or virtual machines) running in parallel to achieve a practical throughput. Use a separate unique <MigrationAdmin> account for each machine, to overcome the limits imposed by Office 365 throttling. Also, each migration machine should be configured with fewer threads (2–4) to optimize throughput. More migration machines are therefore required for Office 365 migrations to achieve throughput rates comparable to those for other target platforms.
Also, migration to Office 365 uses the Internet to transport data, which is typically slower and less reliable than local network connections. Migrator for GroupWise offers several performance parameter settings that can minimize timeouts when data transmissions encounter network delays. These parameters are explained in the below.
Your organization may already have a local Active Directory running for login and security purposes. If so, Microsoft’s Online Services DirSync tool can provision Office 365 with object data from the local AD. The DirSync tool also creates the O365 mailboxes as it creates the accounts. If you don’t already have a local AD, you could install, configure and provision one from scratch, and then use the DirSync tool to provision Office 365.
Migrator for GroupWise and Quest Coexistence Manager for GroupWise (CMG—a separate Quest product, not included with Migrator for GroupWise) can automate object and group provisioning to a local AD. You could also provision the local AD with Migrator for GroupWise alone, or with Quest Migrator for NDS (another separate product).
Provisioning Office 365 from a local AD by Microsoft DirSync permits what Microsoft calls single sign-on, or identity federation, so your users can access Office 365 services with the same corporate credentials (user name and password) they already use for your existing local AD.
If you do not have a local AD, Migrator for GroupWise can provision Office 365 directly from the GroupWise source, and can also create the O365 mailboxes. Alternatively, you could provision Office 365 manually, by scripting, or by the Office 365 portal.
Microsoft’s Calendar Federation requires a local Exchange server, but enables bi-directional free/busy between Office 365 and local Exchange users, among other coexistence features. Quest CMG can also leverage this configuration to provide free/busy lookups with GroupWise users.
CMG can provide direct mail and free/busy coexistence between GroupWise and Office 365, and does not require a local Exchange server or Calendar Federation to support bi-directional free/busy queries. CMG’s Directory Connector, however, does not support direct directory coexistence between GroupWise and Office 365. You may want to consider this reasonable workaround for GroupWise-to-Exchange free/busy coexistence:
NOTE: Provision Office 365 from a local AD, and establish a "two-step" directory coexistence between the two by:
When migrating to Office 365, it is particularly important to involve your IT security specialists early in the project planning, to accommodate all of the account permissions and configuration requirements that are unique to the hosted Office 365 system.