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Cleaning Up After Your Email Archive Migration

We were recently asked if we had the ability to clean-up or purge data when migrating Enterprise Vault archives to Office 365.

The answer was YES – in theory – we can.  Having said that, regardless of the archive you have or the mechanism you chose to migrate your data, the practicalities of ‘clearing up behind you’ are not as straightforward as you might think.

Overall, cleaning up data post migration is a good idea:

  • It makes financial and operational sense
    Maintaining a defunct archive on-premises (or in the cloud) is an unnecessary overhead.
  • It minimizes risk (and costs)
    If your aim is to make Office 365 the ‘single source of truth’ for Information Governance and eDiscovery, copies of data left ‘hanging around’ may still be deemed relevant in an eDiscovery case or contain the personal data you’ve been striving to make secure https://eugdpr.org/.

But not so fast….

We recommend you think twice before pressing the delete button on your legacy archives immediately after a migration.

Here are just three of the scenarios we’ve seen:

  • A change in target: There’s been more than one situation where – for whatever reason – customers have had needed to switch halfway through a migration to an alternate destination. This of course would not have been possible (or would have relied on restoration from backups) if the archive data had been purged automatically as it was moved.
  • Corruptions in the source: There are a number of reasons why your old archive might become unreliable. Missing attachments, lost folder identities, even message corruptions from bugs introduced and then fixed years ago in the archive software – we’ve seen it all  https://www.transvault.com/blog/billions-emails-moved-0-00-failures/.  Fixing these corruptions typically involves performing remediation on the source archive database or setting up additional migration rules, and then, you guessed it, re-migrating the data.
  • The legal department gets ‘more engaged’: We’ve seen it many times where the legal team has not been fully ‘in the loop’ on the outset of a migration project, but then start to make (often stringent) demands in relation to the migration later on.  Keeping a copy of the archive may be one of those demands.

Top Dos and Don’ts when it comes to cleaning-up post migration:

  1. Do involve your legal team in your migration project from the ‘get go’ and guide them through the points in this blog.
  2. Don’t delete as you go. Give yourself an “air gap” in your project plan between migrating your data and deleting the corresponding archive (see next point).
  3. Do check the results of the migration. Obviously, it’s not possible to look at every single item, but make sure you review a random selection of migrated emails across a set of pilot users who represent a broad spectrum of your organization.
  4. Do get a reliable inventory of everything that’s in your archive before you move, as well as proof that what you select to move is successfully received by Office 365. Good due diligence in this area is vital for ongoing legal and compliance purposes.
  5. Don’t assume that deleting your old archives and dismantling your archive server is enough to minimize your litigation and compliance exposure. Your clean-up should include old off-site backup tapes, test archive servers and (dare I say it) PST files on laptops and network shares https://www.transvault.com/blog/alleviating-the-pst-headache-part1/. We know of several organizations that have been ‘caught out’ in this respect, and have felt both the financial and the reputational impact.
  6. Do consider having a single, secure backup. Even if you are sure everything has been properly migrated and accounted for, maintaining a backup, say, on Azure archive storage, is a belt and braces strategy. Azure has a cold storage tier which is perfect for this purpose and access to this with exceptional data management functionality can be provided with solutions such as that from Hubstor. https://www.hubstor.net/cloud-archive/

This is how TransVault deals with archives as you migrate…

After migrating each user, TransVault automatically removes (zaps) settings and permissions from Enterprise Vault to prevent users accessing this data, ensuring that you have a clean cut-off point from which to start enjoying the benefits of Office 365.

TransVault is non-destructive to the source data and leaves it safe for you to make your own decisions about when and how to disconnect it from your organization.  A TransVault migration offers you the control and flexibility to cope with the scenarios which we’ve described above, and anything else you might encounter.


Posted by: TransVault