Superuser deleted after software installation
 

I would like to know what's behavior if I delete a superuser account which use to install software after the installation. Can I still execute the software? and it can execute as superuser privilege?

You need the Sysadmin account.
For sysadmin tasks.
Software usually need no superuser privilegs to be executed.

You should use a secure password for that.

where did you delete it from? Why didn't you restored it? Whithout root account the host will be useless (sooner or later). What kind of software is it? Some of them need root account, others work with their own ones or takes the account of the actual users.

The root account exists:

1. establish ownership of system files.
2. update the system
3. configure the system
4. establish a security plan
5. used to start privileged services (sshd, change passwords, login, resource/quota accounting...)

If the system is carefully configured, it will work just fine without a root account... But without that "carefully configured" effort, you will not be able to configure it. At this point, think of the system as an embedded device, with only user access. You can't configure it, you can't update it....

Most software/application/program do not need to run as "root". They are always meant to execute by simple "user" account.

Only a super-user can execute a super-user (root) privilege. We do not use the term "super-user" here: superman exists only in other worlds. In unix/Gnu/Linux parlance we use the term "root". Some X managers or desktop environments do not allow root login in "X" or GUI level. However, as always, you can login as "root" in run-level 1. There, using the command useradd and groupadd, you can create a user or users (as many as you can) with a set-user-root privilege (sudo or su or gksudo, etc.) an account endowed with root privilege even while running in X. If you need further clues how to do this you may post it here.

Pay attention to pan64 and jpollard's comments above because these are fundamental principles.

Hope that helps. Good luck.

m.m.

https://help.ubuntu.com/community/Sudoers

The short answer is a host can have more than 1 superuser.
Deleting a superuser will not prevent the programs they installed from running, if installed correctly, or through a package manager.

Actually, I distinguish between vendor-supplied software, and local software which is installed by (sometimes, "written by") the system's local community of users.

I set up an account, perhaps called maint (yeah, I'm an old VM/370 guy ...), which is responsible for ... and which owns ... directories such as /usr/local.

It is important that software which is "in a public place" must not be modifiable by the people who are intended to use it. Thus, the "local" applications are installed by, and thereafter owned by, this user ... which is not privileged, and which cannot issue the sudo command. This protects the software from modification ... intentional, or by "oopsie!"

Incidentally, my "ordinary user" accounts do not have the ability to issue sudo. "Yes, I own a Captain Marvel suit, but my name is not Billy Batson, and I nothing happens when I say, 'Shazam!' "