If a large number of oversized mailboxes need to be migrated, consider the time and performance impacts on the existing system. Migrating large volumes of data can degrade performance for other users. It may make sense to delete or archive older material before migrating these mailboxes.
If a user – such as an executive PA - has mailboxes which comprise numerous calendars and lots of contacts and groups it will take longer to migrate than the same size mailbox that is just mail items.
Locating and importing Personal Storage Tables (PST files) can be tricky, as these are likely to be located on PCs and laptops dotted around the organisation. There are Exchange PowerShell scripts to help with this. Alternatively a range of third-party solutions is available.
Although hardly mentioned as a potential hurdle by those respondents that were still at the planning stage, installing certificates came quite high on the list of bugbears for those who had completed a migration. There appears to be a degree of confusion about which certificates are required and where, with some people believing that each named element needs its own certificate.
However, while organisations may require many site names for AutoDiscover, Active Directory, ActiveSync, OWA, etc, they do not need a certificate for each of these.
The requirement is for only one certificate per site. Internet-facing sites require external certificates; internally facing sites require internal certificates. So if the organisation has 50 internal sites and one external site, acquire a single third party certificate for the external site, and raise an internal certificate authority (CA) and create and deploy certificates for the internal sites using this CA.
Experts advise firms to obtain a certificate for a single host that contains Subject Alternate Names and install that using the Exchange Management Console or PowerShell. The Exchange Server Deployment Assistant2 will allow the migration team to step through what is required, such as certificates and where they should be installed.
Outlook Web Access configuration
Getting OWA to function during the migration can be a source of frustration. This is because the CAS installed as part of the Exchange Server 2010 package needs to be configured to redirect users to the legacy front-end. When a user connects to Exchange Server 2010 CAS for OWA and the mailbox is still on Exchange 2003/2007, the client will be redirected to the old 2003/2007 front-end server.
Once the clients have been updated the redirects are removed and the DNS will direct the OWA traffic to the new front-end server.
Moving from Lotus Notes
About five per cent of the respondents to Computing’s survey had migrated from a Lotus Notes environment to Exchange 2010. This is certainly a more complicated proposition than moving from a legacy version of Exchange.