Overview
This blog post details the issues encountered recently in
migrating a customer to the Microsoft Office365 Solution
using the built-in E-mail migration tool (aka Move Mailbox tool or MMT). It should be noted that many of these issues are well known by Microsoft and they are working on fixes or workarounds for some.
The following are a high-level list of the areas the MMT has issues that were experienced during the migration of this customer to the Cloud.
- Limiting Choices
- Speed
- Reporting
- Data inconsistencies
Limiting choices
Up until recently the Microsoft's MMT was just one
of many options for migration. But recent changes to the Directory
Synchronization tool (Dirsync) now misleads customers and partners to think they can only use the MMT
instead of 3rd party migration tools. The recent change was that
once you use the Office 365 Dirsync the only way to get a mailbox provisioned in 365 is to run
it through the migration process using the MMT. The Office 365 Portal UI
actually will point out that once you add a license to a mailbox you MUST
migrate that mailbox using MMT to have the new mailbox provisioned.
Now this would not be so bad If there was an option to only
provision the mailboxes with the MMT and migrate with another 3rd
party tool but that feature is not available or is not exposed at this time. Some of the 3rd party tools have worked around this issue, but I don't have details on that just yet. It baffles me that the dirsync tool was
changed force customers to use the MMT without any clear communications to the partner or customer channel.
Workaround:
To work around this issue you would have to change the MIIS attribute
mapping in Dirsync to leave out some of the
attributes that trigger this situation, or don’t use Dirsync at all. Editing the attributes mappings for Dirsync is technically not supported and can cause other issues. Not using Dirsync limits customer options for
Single-Sign-On (SSO) and integration with AD, which is not a great story for the cloud. Some 3rd
parties have created their own dirsyc options to work around this, but they
lack the integration with AD and may not be compatible with SSO or other features
that require dirsync.
Speed
Acording to their own support staff Microsoft is constantly experiencing “congestion” on their
migration servers for MMT that is causing the following error to happen to
random mailboxes regardless of size, complexity or status.
E-Mail Migration failed for this user because no e-mail
could be downloaded for 1 hour, 20 minutes.
The main solution that Microsoft is looking into to remedy
this is to change the timeout to 4 hours.
So considering that a new batch cannot start until another batch
completes, now we’re going to waste 4 hours of migration time instead of 80
minutes. When the MMT is having “congestion”
issues, normally only between the hours of 5pm EST and 6am EST, you will see
the following when you open Exchange Control Panel (ECP) and select any information from the MMT:
And don’t get me started about the actual migration
speed. In the time it took to move 50
mailboxes with the MMT we migrated in parallel over 500 similar sized
mailboxes with another 3rd party tool. The MMT tool only runs about 5-20MB per
minute, when we’re getting over 5 times that speed with other tools.
Lastly, once you start a batch you are stuck with it until
it’s done or you cancel it. The MMT tool does not support running multiple
batches at the same time, although you can run up to 50 mailboxes at the same time
in the same batch. So say you have one
25GB mailbox in a batch and then you have another batch of users that need to
start the next night. When you come in
to start the next batch you notice that all but one of the mailboxes in the
first batch are done, but the large 25GB mailbox is only 50% complete. Your
choice now is pain or more pain…… i.e.
you can choose to stop the current batch with one user or wait until it’s done next
Tuesday. There is a pause button in the MMT tool, but it won't acctualy pause since it
actually cancels the migration and stops the batch. So you stop that batch, start the next batch. Well now you need to remember to come back around and create another batch to
finish up that large mailbox at a later time, which means it’s incomplete until
that is done.
Workaround:
The only workaround at this time is to re-submit failed
timeouts over and over again until they are successful. Not only is this workaround inadequate, but
it costs customers and partners more money because they have to have resources babysitting
the migration process all night in addition to support resources during the
day. The migrations tend to go well into the working day which unfortunately costs customers
downtime as its eating precious network bandwidth during a time when they are
trying to get their business done. As
you can see from the following screen-shot we had to run 31 separate batches
for a migration that should have only been 4-5 tops.
The reporting capabilities of the Microsoft tool at first
seem to be adequate, but once many migration batches are run it becomes
apparent that reporting the success and errors in downloadable reports does not
always work. The screen shots below show
two batches that completed, but only one has the downloadable reports
available.
The only way to get any good data from MMT is
through PowerShell, but there is no module for directly downloading the
statistics. You could try and download
them from each batch, but that proves to be unreliable because as you can see
above not each batch gets a migration report.
So, you essentially need to run some PowerShell commands
based upon a CSV that has all the e-mail address of the users that you
migrated, luckily we had one of those.
The only remaining issue with this approach is that the throttling
policy can make these take hours to complete.
$mailboxes = import-csv mailboxes.csv
$migrationStats = foreach ($address in $mailboxes)
{Get-MigrationUserStatistics $mailbox.UserPrincipalName}
$migrationStats | export-csv migrationstats.csv
Data Inconsistencies
The one thing you can say about the MMT is that it’s
consistently inconsistent
The following user had different data
every time we pulled statistics for them.
Within a 15 minute period the percentage complete went from 87% to 45%
and then back to 95% while the numbers reported in the tool were WAY off.
Riddle me this: How can a mailbox be completed, but change from 14% to
17% to 22% and then eventually 95%?
The
following screen shots show the MMT GUI is incorrectly indicating that one
# items were migrated, even though PowerShell shows different numbers for # of
items were migrated. When we re-ran
these users all their mail was duplicated because we got bad data from the
MMT. These are just two examples
of the 20 mailboxes that had this issue.
Another Mailbox for Keith:
Workaround:
Only trust half of what you can see and none of what the GUI
says. If the migration statistics for
one mailbox say the MMT moved 2500 items, run the
“get-mailboxstatistics” command against that mailbox and verify it thinks there
are at least that many or more in the mailbox.
And if the MMT says zero, then you better not trust it at all and
verify within the mailbox the actual amounts by opening the mailbox in OWA using
the migration account with permissions.
Summary: