TIP: Speed up your migration, disable searching for duplicates

Here’s a tip that could decrease your migration by an hour or more on average.

By default, we search the destination server if we have migrated the item before creating it. We do this to ensure that in all cases we will never duplicate items in a mailbox.

Well, if this is the first time you are migrating the mailbox, we won’t encounter duplicates because there is nothing to duplicate! Our search to the destination mailbox will always never return a match.

You can disable duplicate searches by selecting the advanced option “do not search destination for duplicates before migrating items” on the connector (to apply to all mailboxes) or on the individual mailbox itself.

Let’s say on average the search takes 1 second (there are a lot of factors that determine how long this transaction will take). A mailbox with 10,000 items will be reduced by 10,000 seconds, which is 167 minutes or 2.8 hours. As you can see, every transaction adds up.

You should not disable duplicate searching in the following cases:

• You have selected the advanced option “do not resume from last migration”
• You have newly configured a mailbox that you have previously performed a migration for (newly configured mailboxes do not have mailbox state to allow us to resume from where we left off)