I have a larger site that is broken into sub-domains using MSM. Each of these sites has its' own group of employees that manage that section. My thoughts were to create the Member Groups to reflect these employee groups and assign them proper access rights to each sub-domain. Each sub-domain has its' own CP access admin location to keep it simple for them.
So: blog.domain.com would have a group called Bloggers in the Member Group and they would log in at blogadmin.domain.com
The Admin accounts can switch between sites at the CP located at admin.domain.com under the MSM drop-down. They have all the access they need to each site as assigned. Bloggers could attempt to log in at admin.domain.com, but are rejected and told they don't have permissions. They can only log in at blogadmin.alamode.com which has the CP only show them the blog.domain.com site functions assigned to them and no other sites show in the MSM drop-down.
When I did this, I created a user who did NOT have access in the primary site, only the sub-domain like I needed. The problem came when I went to either site and tried to list members. I received an error stating that I was missing an ID.
Looking through the EE DB, I see that the Member Groups have a DB field for 'group_id' and 'site_id', but the Members table only has 'member_id' and 'group_id'.
How do I create members without receiving errors???? This makes me feel like a complete newb.
I have the latest of both EE and MSM installed.
If you're using version 2.5.3, you might have hit this open bug where Members Groups aren't added to all sites in an MSM install. There's a hotfix you can download there.