Learn the list of different run levels in HPUX and their roles. Also, see how to check the current run level in which the system is running.

A run level is the state of a system depending on which system services will spawn. Normally lower run levels are having fewer services available for the user and mainly used for administrative purposes. Higher levels have more services available and targets end user’s use. In HPUX highest run levels like 5 and 6 are kept reserved for future purposes. We will see the list of run levels and their offerings in the following article.

Current run level in HPUX can be identified using the below command :

# who -r
   .       run-level 3  Jan 19 21:14    3    0    S

The output fields of the above commands are as below:
1. A dot . indicates that the terminal has seen activity in the last minute and is therefore its. i.e. current.
2. Current run-level
3. Timestamp
4. The current state of init
5. The number of times that state has been previously entered
6. The previous state

Read also: Different usage of ‘who’ command.

List of run levels in HPUX

0 indicates shutdown state
S indicates single user mode booted to local console only with root FC (RO) mounted
s indicates the same as S only current terminal acts as system console.
1 indicates the single-user mode with local FS (RW) mounted
2 indicates multi-user state with CDE launched
3 indicates the same as 2 but with NFS
4 indicates GUI (here VUE started instead of CDE)
5,6 indicates reserved to state and not yet defined in kernel code.