Hi Michael, I understand that there can only be one instance of O365 (which means domain B migrating to domain A’s O365 instance will have to create mailboxes first in domain A’s O365, delete mailbox/instance…etc) & potential for disruption to mailflow as a result of the change, but can you elaborate on the “perils” & issues that you’ve encountered with O365 to O365 migration?
Thanks http://grey.com/disclaimer From: [email protected] [mailto:[email protected]] On Behalf Of Dennis Hoefer Sent: Wednesday, May 14, 2014 10:19 AM To: [email protected] Subject: [Exchange] RE: Cross forest to cloud migration question Michael, I very much appreciate your reply and opinion. From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Michael B. Smith Sent: Tuesday, May 13, 2014 5:31 PM To: [email protected]<mailto:[email protected]> Subject: [Exchange] RE: Cross forest to cloud migration question I would not do an o365 to o365 migration. Those are truly fraught with peril. From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Dennis Hoefer Sent: Wednesday, May 7, 2014 7:00 PM To: [email protected]<mailto:[email protected]> Subject: [Exchange] RE: Cross forest to cloud migration question Thanks Michael, Side A is in a hybrid scenario, they’ve had on premise and Office 365 mailboxes coexisting, and far as I know, their Exchange environment is still in place. Two thoughts, whatever partner they are working with had apparently suggested having Company B migrate to Office 365 first, then do an Office 365 to Office 365 migration. Or, since their Exchange environment is still running, we’ve thrown out the idea of migrating there first and then jumping to Office 365. I believe the whole thing is going to be painful, but would either one of the above lessen the pain point in your opinion? From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Michael B. Smith Sent: Wednesday, May 07, 2014 4:37 PM To: [email protected]<mailto:[email protected]> Subject: [Exchange] RE: Cross forest to cloud migration question I believe this would be supported only in a hybrid-scenario. But I’ve never run one of those for what you describe. I think it would be a little painful. From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Dennis Hoefer Sent: Wednesday, May 7, 2014 4:53 PM To: [email protected]<mailto:[email protected]> Subject: [Exchange] Cross forest to cloud migration question My apologies if this has been asked before, but I don’t recall seeing a discussion on this particular scenario. We are doing groundwork for a potential company merger and discussing AD and Exchange migration. Merged company will retain the corporate name and therefore AD structure of Company “A,” which is in the final stages of migrating from in-house Exchange to Office 365, Company “B” has mail in-house on Exchange 2010. I’m finding information on cross forest Exchange migrations, and plenty of info on straight Office 365 migrations, but not coming up with much on scenarios involving cross forest migration of Exchange 2010 mailboxes directly to Office 365. Migration of Company B would involve around 250 user/machine accounts and 200 mailboxes. Any links to specific information, plans, recommendations or advice would be appreciated. Dennis
