single user mode

[Radhakrishnan Venkatara]

hai all,

i have a query what does single user mode (init 1,S,s) denotes.
the above 3 are denotes single user mode only.As i know some of them init 1 denotes single usermode with all filesystems getting mounted.
IN init s only root get mounted and only sysinit processes of inittab gets excuted.
in init S is same as init s but the difference is your terminal will become the system console (here how does my terminal becomes system console ? what does it mean ? If connected from network ,I will get disconnected while going to single user mode ( there is no networking in single user mode ))
please explain me about this

radhakrishnan

[Steven Sim Kok Leong]

Hi,

One use of single-user modem is when you are performing full system backup such as using HP-UX fbackup, it is preferable to shut the system down to single-user mode so that there are minimal file changes or unflushed files during your backup. This is to preserve file consistency in your backups.

Often, this mode is used for maintenance and troubleshooting since it effectively bars connections from remote users.

Hope this helps. Regards.

Steven Sim Kok Leong
Brainbench MVP for Unix Admin
http://www.brainbench.com

[Printaporn_1]

just copy form init manpage
If you enter S, boot
init operates as previously described in single-user mode with the
additional result that /dev/syscon is linked to the user's terminal
line, thus making it the logical system console