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Should move mailbox to Office 365 on working hours RRS feed

  • Question

  • Hi all,

    Can you let me know what may impact to user operations if we migrate mailboxes to Office 365 on working hours? For example using hybrid deployment, staged migration and cut-over.

    What I understand is that:
    - Cut-Over: Because of one single batch for all mailboxes with not large number of users so it should be only cautions at the time changing MX record. During the migration may reduce performance for user accessing their mailboxes?
    - Staged migration: Should not migrate on working hours because we have no idea the exact time that one mailbox on a batch finished so it's quite difficult in supporting users.
    - Hybrid migration: Just want to know more from all of you, just I know that even we don't have to re-create outlook profile but I have no experience about the time it will takes to sync attribute to O365 right after one mailbox migration finished.

    Thanks a lot !

    Sunday, October 12, 2014 4:08 AM

Answers

  • HI Duc,

    During working hours isnt the best option.Depends on how many mailbox and total size it will consume your bandwidth.Users will experience poor connectivity to outlook.If you have large amount of mailboxes and it spans over multiple countries,then best would be to do one for each country or whole migration during weekend.

    I have been moving over 600 mailboxes so far in a hybrid environment.We are only half way and hopefully will be done during next week.Reason we do multiple batches,is because we experience unstable speed.At best so far we manage to get 230MB/min.Also experience migration of some mailboxes stops/fails now and then,so have to remove failed mailboxes and create new batch (nothing wrong with mailboxes,just losing connection to office365).Configuration from our side we cannot see any error that cause slow speed and that migration of certain mailboxes fails(some as low as 100MB in size and less than 1000 items and 100 folders).

    If you have low amount of mailboxes,then after working hours is best solution.


    Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you. Thank you! Off2work

    • Marked as answer by Kzb Monday, October 13, 2014 3:13 PM
    Sunday, October 12, 2014 1:04 PM

All replies

  • hi Duc,

    Let take it one by one...

    1. In cut over the main worry is recreating profile.. migrating data and if users are traveling then it becomes kind of tough if PST is not with you. but it kind of takes less time as you only moving DNS records. and its safe also as you always have a fall back plan in case things dont go according to plan. make sure your DNS provider TTL/refresh time is good.

    2. Stagged Migration: in all the migration jobs all will depend on your UPLOAD bandwidth, latency, load, size of mailbox. so this all will define the time. you need to also see what kind of current system you have as there is some recommendation on scenarios on where stagged can be used or not.

    please see these two links. 1 for scenarios and second one is for the steps to perform stagged.

    technet.microsoft.com/en-us/library/jj898486(v=exchg.150).aspx

    http://technet.microsoft.com/en-us/library/jj874018%28v=exchg.150%29.aspx

    3. coming to HYBRID: this is my fav too... i recently completed for my clients and my company too... here atleast you are not worried about users going offline ... or loosing mails... having said that .. this is true this has the maximum number of moving parts... to configure so i would suggest you configure this and perform a migration using a text mailbox. yes you dont have to create the profiles again. once the user will completely get moved to 365, the users will get an message on outlook about ADMIN HAS DONE SOME CHANGES AND THEY HAVE TO RESTART THE OUTLOOK.

    about time... i guess this we have discussed on point 2 about.

    Let me know if this helps.


    Mark as useful or answered if my replies helped you solving your query.
    Thanks, Happiness Always
    Jatin
    Skype: jatider2jatin, Email: jatinder2jatin@yahoo.ca

    Sunday, October 12, 2014 6:18 AM
  • HI Duc,

    During working hours isnt the best option.Depends on how many mailbox and total size it will consume your bandwidth.Users will experience poor connectivity to outlook.If you have large amount of mailboxes and it spans over multiple countries,then best would be to do one for each country or whole migration during weekend.

    I have been moving over 600 mailboxes so far in a hybrid environment.We are only half way and hopefully will be done during next week.Reason we do multiple batches,is because we experience unstable speed.At best so far we manage to get 230MB/min.Also experience migration of some mailboxes stops/fails now and then,so have to remove failed mailboxes and create new batch (nothing wrong with mailboxes,just losing connection to office365).Configuration from our side we cannot see any error that cause slow speed and that migration of certain mailboxes fails(some as low as 100MB in size and less than 1000 items and 100 folders).

    If you have low amount of mailboxes,then after working hours is best solution.


    Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you. Thank you! Off2work

    • Marked as answer by Kzb Monday, October 13, 2014 3:13 PM
    Sunday, October 12, 2014 1:04 PM
  • Thank Jatin and Off2work for your response and really appreciate your experience that both of you shared with me

    So in short, I see we shouldn't do migration on working hours with large number of mailboxes as well as limitation of upstream bandwidth, right ?

    @Off2work: You said that we sometimes have to remove failed mailboxes and create new batch. That means mailboxes in the batch will be performed one by one and if one get failed, the next cannot be continued? if yes, I have come up a question that can we ignore those cases on a batch or have any methods to track the batch and get notification of errors instead of checking the status manually.

    Also, if we have branches over multiple countries, is it true the O365 subscribed for the Exchange is just at one location/datacenter of MS.

    Thanks !


    • Edited by Kzb Sunday, October 12, 2014 2:29 PM
    Sunday, October 12, 2014 2:28 PM
  • Hi Duc,

    if you have created a migration batch of like 100 mailboxes and 5 fails, the others will continue as normal.When migration is completed,you will get an e-mail (that you have defined during creation of migration batch) with the report of the migration.

    You will need to delete failed mailboxes from the migration batch,then complete the migration.

    Migration are limited by the following:

    Migration end point: this is a endpoint you create before you migrate the first mailbox.It can be set to an amount you want.Its not recomend to set it to high,since it will consume your bandwith,memory and processor.We have set ours to 75 to fit our environment.

    There are "limits" of 20 concurrent moves pr CAS server and 5 for each mailbox database.This is not accurate,but a good pin point.

    For Exchange 2010 server this can be tweeked ,but on Exchange 2013 there is no need.

    (we have only 2 servers with cas and mailbox role,and we manage to get 75 concurrent moves).

    As for which datacenter your mailbox is moved to,i think its closes datacenter region that your server resides.

    And your migration is also limited to your upstream bandwith.

    Here are some usefull links:

    Exchange Online migration performance and best practices:

    http://technet.microsoft.com/library/dn592150(v=exchg.150).aspx

    Network performance factor/test:

    North America: http://na1-fasttrack.cloudapp.net

    Hope this helps


    Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you. Thank you! Off2work

    Sunday, October 12, 2014 3:35 PM
  • Thanks Off2work for supporting.

    Just a further question want to ask you when I see you may get experience & knowledge for that: In case we have 2 forests with different SMTP email addresses, is that possible to deploy hybrid deployment and do migrating Exchange on-premise  to one tenant Office 365 simultaneously?

    Monday, October 13, 2014 5:22 AM
  • Hi Duc,

    it is possible,but you will have to configure all domains in your tenant.We are multitentant environment with over 10 domains and all is working fine.

    You will also have to add txt and mx record with info specified during domain configuration.

    But to mention we use 1 single "domain" in the cloud where email is @domain.mail.onmicrosoft.com.

    Please also read Exchange Online limits,so it doesn't come as surprise when you are migrated: http://technet.microsoft.com/en-us/library/exchange-online-limits.aspx

    Only single item recovery is "Recover deleted items" which is by default 14 days.You can extend this if wanted or you will need to use another backup tool that supports Exchange Online.

    Also Send as function doesn't work in Hybrid environment,which means that user with mailbox in Exchange online wont be able to use the function if the shared mailbox is On-Prem.

    Cross permission doesn't work for calendar either,so plan your migration carefully :)

    Feel free to ask if any other questions,will be glad to help.


    Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you. Thank you! Off2work

    Monday, October 13, 2014 7:11 AM
  • Thanks a lot Off2work. It is really useful and informative.

    So let's say that we can deploy Hybrid environment simultaneously with two separated on-premise AD forest and only one tenant Office 365 and co-existence including mail flow routing still works fine? If yes, is there anything needs to be considered when setup ADFS and DirSync please?

    What if using FIM (Forefront Identity Manager) to consolidate AD in the case of multiple forest before migrating email to Cloud, is that possible to setup DirSync & ADFS once for all forest?

    P/S: I am sorry but If you see it is going too far from the topic I will open a new thread for my recent questions



    • Edited by Kzb Monday, October 13, 2014 8:29 AM
    Monday, October 13, 2014 7:53 AM
  • Hi Duc,

    for e-mails to successfully migrate to Exchange online there are 2 requirements.

    1. All mailboxes must have @domain.mail.onmicrosoft.com as e-mail alias.

    2.Account must be successfully synced to Office365.

    3.Only domains that are configured in Office365 is accepted,so if an account has a email domain that is not configured it will fail.

    Other factors that determine if migration will be successful is:

    If you are using Lync and voicemail,this have to be setup and configured in Office365,if not Voice mail has to be disabled.

    If you use Security groups to grant access to shared mailboxes,these groups must be mail enabled security groups (its safe to set them to hidden).

    Useful info for best user experience:

    When user sign in to office365 portal they will have to use their UPN,so best is that UPN is same as their primary e-mail.

    So far user logon name pre-2000 is not used in the cloud.

    In our environment we only sync certain OU to the cloud,so plan your Dirsync carefully as well.

    This is what comes up right now,please feel free to ask.


    Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you. Thank you! Off2work

    Monday, October 13, 2014 8:37 AM