I was wondering if anyone knows... When you move mailboxes from one storage group to another, does it generate the same number of log files on the source DB as on the target? I've found some anecdotal evidence on the internet that the target is far more affected by log file generation than the target but I was wondering if anyone knows definitively? -Patrick

The target is where heaviest amount of transaction logs will be generated -http://technet.microsoft.com/en-us/library/bb738147(EXCHG.80).aspx Moving mailboxes is a primary capacity factor for large mailbox deployments. Many large companies move a percentage of their users on a nightly or weekly basis to different databases, servers, or sites. If your organization does this, you may find it necessary to provide extra capacity to the log LUN to accommodate user migrations. Although the source server will log the record deletions, which are small, the target server must write all transferred data first to transaction logs. If you generate 10GB of log files in one day, and keep a 3-day buffer of 30GB, moving 50 2-GB mailboxes (100GB) would fill your target log LUN and cause downtime. In cases such as these, you may have to allocate additional capacity for the log LUNs to accommodate your move mailbox practices.