'morning all, I see from my new RHEL4 sysadmin guide that uid's up to 500 are reserved for system use. When I first began setting up my Unix userbase some 15 years ago, I unfortunately chose to start at uid 100, so I now have to change the uid's of some 400 users, 36 million files, on a hundred or so boxes. OK, this is do-able and should be more-or-less 'transparent to the user'. (Since I'm going to make a change, should I start at 1000 and change the lot? How reliable is the 500?) The thing that concerns me more, is the plethora of reserved usernames. There seems to be no rule to distinguish a reserved username (presumably the list in the RHEL sysadmin guide is going to grow) and its only a matter of time before some newly allocated name collides with one which has been given to a user. In fact, I cant find anywhere what the rules are for usernames. Character-set? How many chars? Pity that reserved names arent systematic in some way (like always starting with sys_ or somesuch). I'm not looking forward to the day when a new system-username duplicates the username of one of the directors, which he has had for the last 15 years, and which is also his email address held on mailing lists and institutions all over the place... Any advice out there? Cheers, Terry.
