UNIX for Dummies Questions & Answers

Hello,

I have a small problem and would be happy if someone could help me to find a solution:

A machine ("server") makes backups of different computers ("clients") using rsync. Users and groups are keept, so that it's possible to copy them back to the client if required. The number of groups and users changes every day. But how can a support member access one of these files on the server? Either the support user has to get root-rights, but this is not a very secure solution or I run a chown after each backup - but this would make the backup unusable, because it can not be copied back 1:1.

I guess there is no chance to give root rights to the support group which just takes effect on one folder containing all the backups?

Any ideas? Thanks!

If this is homework, I can't tell what canned answer they want. If it isn't, please tell us more detail about the system.

Hi, this is no homework, it's an existing and running environment.

The "Clients" are different Webservers, with multiple accounts, users and groups. There are daily changes on the datastructure, new accounts are generated (and with this accounts new users and groups on this client machines). All groups which are generated on these machines have one thing in common: the group itself is member of one "backup" group.
Now there is a backup/storage server connects itself to the client once a day and makes a backup of all files and folders via rsync. During backup the original user and group rights are keept - this user and group does not exist on the storage server, so I only can see the id of the group. So if a user deletes files on his client (webserver) unintentional we are able to copy the content back and of course on this machine user and group exist and therefore everything is back to the original state again. All this works fine so far.
But - if a some calls the support weather there exists a backup of a certain file and they want to check if there is a existing backup on the storage system this is only possible if they access the storage server with root rights, because the groups and users on the storage system do not exist. Therefore I'm searching a better solution...

With groups and users continuously changing in an uncontrolled manner, I don't see a way to avoid collisions, i.e. a current UID potentially overlapping with a past one, or even a local one... I think you'll need to make a plan about how to map foreign UIDs and GIDs into local ones.