[CentOS] UID/GID migration vom C6 to C8

Hello.

We have to migrate an old Centos 6 to Centos 8. C6 has UID/GID starting at number 500. I the Users should possibily keep the existing UID/GID as on the old system.

I changed on the Centos 8 system, in /etc/login.defs, the lines UID_MIN/SYS_UID_MAX and GID_MIN/SYS_GID_MAX:

# # Min/max values for automatic uid selection in useradd # UID_MIN                   500 UID_MAX                 60000 # System accounts SYS_UID_MIN               201 SYS_UID_MAX               499

# # Min/max values for automatic gid selection in groupadd # GID_MIN                   500 GID_MAX                 60000 # System accounts SYS_GID_MIN               201 SYS_GID_MAX               499

and extracted all users and groups with UID/GID greater than 499 from the old system and inserted in the corresponding files (passwd/groups/shadows) on the new system.

So wanted to ask if this is a valid thing to do? Especially regarding security of the new system. Can it create problems in the future (updates etc.)? It is a simple LAMP server.

Thanks, Thomas