I have 9 User ID's that I want to make consistent accross two macs:
This should be no problem for the iMac because I made a clean install on a new hard drive (with Mountain Lion). Some will be new users. Some will be migrated from the previous setup on a previous hard drive (with Leopard). It should work if I do it in the order I want. (I saw advice from Pondini in the pink & green boxes in Problems after using Migration Assistant).
On both Macs I use UID=501 as an admin account.
The MBPro already had three User's set up. Only one was a User with data that needed to be preserved, but I wanted to change its UID to match my scheme for both Macs. (I know there is the User ID field in the "Advanced Options" of the Users & Groups preferences; but I did not want to manually change that.) I made a clone of the MBPro drive and thought I could delete all but the 501 admin account and then use Migration Assistant to bring that User account back to the MBPro in the sequence I wanted for the UID's in a similar manner as I hope to do for the iMac.
On the MBPro, I also noticed that several group IDs appeared in the Users & Groups preferences that included Group ID's including ones with numbers 506 and 508 that I wanted to use for the Users. It may have acquired those GID's from connecting and sharing with the Users and Groups on the previous iMac setup. Since those GID's were not needed yet on the MBPro (and I think no files on the MBPro have permissions set with those groups), I thought if I deleted them then it would free up those ID's to be used for my User ID setup sequence. The MBPro currently has Lion. I thought I would get the Users set up in my desired sequence, then update it to Mountain Lion.
The above is background for the problem below.
I successfully added users up to UID=505 on the MBPro. Then when I attempted to add the next user, it assigned UID=507 (skipping 506).
Where do I look and how can I eliminate any lingering references to UID or GID=506, so that I can successfully add a new user with UID=506?
I prefer to avoid changing things manually or with terminal. I want the system to do it.