I came across an interesting issue today where I couldn’t install the Lync 2013 SQL Mirror databases.
After I published the topology to create the mirror databases I got the below error and the sql mirror database installation failed.
“Mirroring cannot be setup unless SQL server service runs under a network service account, virtual account, local system account or a domain account.”
The SQL services were already running under a domain account so this confused me. I checked the SQL services on the principal, mirror and witness servers and the sql services were running as a domain account with the username in the format of firstname.lastname@example.org
I changed the format of the username so it was domainuseraccount and restarted the sql services on all sql servers.
I publish the topology again and created the mirror database again and it worked !!!!!