How does EVComplete handle large Enterprise Vault archives?

Overview

When migrating data to O365, customers are limited to 100GB for both Primary and Archive mailboxes.  When reviewing the sizes of EV archives, it is important to consider how Cloudficient plans to migrate "large" archives.  We will define a large archive shortly.  

EV reports archive sizes based on the compressed size.  During the migration, this data is uncompressed.  For example, an archive showing as 40GB compressed, will uncompress to approx 64GB's.  We produce this average by using a multiplier of 1.6 x the compressed size.  A "large" archive is considered anything greater than 62GB compressed as this will uncompress to approx 100GB.  In this scenario, if we are migrating all EV data to either the primary or archive mailbox, we will hit the quota and stop.  

The question is how EVComplete handles these situations.  Cloudficient has the following available options that assist the customer with these quota constraints that Microsoft has on its customers. 

Options for production mailboxes

• Filter data out based on either Age or Shortcuts. When using an Age filter, it will apply to data that is split between Primary and Online Archive mailboxes or a single mailbox (e.g. migrating all data to primary). 
• Distribute data between Primary and Online archive mailboxes based on shortcut. I.e. migrate non-shortcuts (EV data that does not have an associated shortcut in the mailbox) and/or shortcuts (data in the mailbox with a pointer to the EV data). This is a preferred method as it maximizes the quotas for both mailboxes and keeps the mailboxes in-line with what users are already used to.  
• Virtual Split the archive to a series of shared mailboxes. EVC will tally the total size of the archive, create the shared mailboxes, and split the data across them not to exceed 50GB each.  
• Ask Msft to manually expand the online archive to accommodate the migration (in advance).  Chances are they will say no and request you send them the data in PST files instead. Cloudficient cannot help with extracting the data to PST files as this will need to be done using the native EV export wizard. 
• Rely on auto-expanding archives. Anything over the initial quota limit will migrate at roughly 5GB per week.  We do not recommend this option for archives exceeding 100GB compressed.  Virtual split is the preferred method. 

Options for Leavers

A leaver is an EV archive that is 'ownerless'.  The user no longer has an AD account or Exch mailbox.  

• Filter data out based on Age
• Virtual Split the archive to a series of shared mailboxes

Notes:

When using an online archive mailbox, an MRM policy should not be configured such that it moves mail from the primary to the archive during the migration process as it will cause "competition" for space during the auto-expansion process.  We want to maximize all 100GB of primary and 100GB of archive. MRM can be enabled post migration.