When Microsoft launched Exchange Server 2010, it introduced the Personal Archives feature. Personal Archives are...
somewhat comparable to personal storage files, but hosted on the Exchange server in regular mailbox databases. The tradeoff to using Personal Archives is that you needed an online connection with the Exchange Server to access them.
With the release of Exchange Server 2010, Personal Archives had to be located in the same database as a user's primary mailbox. While this might have been fine for some customers, many customers asked for more flexibility with storing the archive mailbox in alternate locations, like on another database or on another server. Exchange 2010 SP 1 loosened the requirements and allowed the archives to be hosted on any database or server in the entire Exchange organization.
Because of the benefits of a hybrid Exchange deployment, you can also store Personal Archives in Office 365 while keeping the primary mailbox on-premises. This option is referred to as Exchange Online Archives and is available as a separate SKU in Office 365 or Exchange Online.
The value of online archives
Using Exchange Online Archives allows you to provide users with the functionality of an archive without necessarily having to maintain the infrastructure to support it. This puts you in the unique position of importing existing PST files into Exchange with little to no additional effort. Not only will you get rid of the burden of running PSTs in your environment, but Exchange Online Archives also can protect stored data.
Another benefit -- and one of the main reasons why Exchange Online Archives is used -- is to offload data from the primary mailbox to the archives. Because Exchange actually moves the item with no stubbing, the items and their overall footprint in the primary mailbox will decrease. This results in a smaller OST file when working in cached mode and an inherently snappier Outlook experience.
This is especially true in environments that cannot yet take advantage of the new Outlook 2013 slider. The slider allows you to specify how much data you want synchronized to your local OST file. In previous versions of Outlook, the entire primary mailbox is cached.
But as good as this option seems, there are some specifics to keep in mind. When Exchange Online Archives will primarily be used to replace PST files, there will be some additional things to think about.
How does Exchange Online Archives work?
From a functionality standpoint, there is no difference in how Personal Archives and Exchange Online Archives work -- only the place they're stored is different. This means the same retention policies and retention policy tags are used to determine what gets moved to the archive. Users can also drag and drop items to the archive, but this is strongly discouraged.
The main difference between having archives on-premises or in the cloud is the dependency on a hybrid configuration. Technically speaking, the hybrid configuration doesn't have to be completely configured; you don't need mail flow between Exchange on-premises and Exchange Online if you're only using archives. However, unless you're trying to manually set up the hybrid configuration, the hybrid configuration automatically takes care of this in Exchange 2010 SP2 onward.
Click here for part two, which covers the best practices for using Exchange Online Archives.
About the author:
Michael Van Horenbeeck is a technology consultant, Microsoft Certified Trainer and Exchange MVP from Belgium, mainly working with Exchange Server, Office 365, Active Directory and a bit of Lync. He has been active in the industry for 12 years and is a frequent blogger, a member of the Belgian Unified Communications User Group Pro-Exchange and a regular contributor to The UC Architects podcast.