HP-UX

Use the install/recovery CD/DVD. This will allow you to get the box booted in single-user mode and change file permissions. You may need to chroot.

How did you go single user mode?

These steps will get you booted in single-user from the install/recovery CD

Booting IA64 system from Install media to Recovery Shell
1) Insert the HP-UX 11iv1.6 DVD into in drive and power on the system
2) During the boot process, select the EFI Shell option, press enter.
3) Shell> edd30 on <<<-- enter
Look at the list of devices (displayed as fs0, fs1, etc.) and identify
DVD-ROM device entry.
E.g.: fs2 : Acpi(PNP0A03,0)/Pci(3|1)/Ata(Secondary,Master)/CDROM(Entry1)
4) Type device name at the prompt.
E.g. Shell>fs2: <<<-- enter (don't forget the colon)
5) Type install to start the HP-UX Boot Loader.
E.g. fs2:>install <<<-- enter
6) Select Recovery Shell option

Select
Run a Recovery Shell
Would you like to startup networking at this time/ [n] n
Loading the recovery commands
HP-UX SUPPORT MEDIA
WARNING: YOU ARE SUPERUSR !!
...
Press (return) to continue.
HP-UX Recovery Media Main Menu
s. Select a file
b. Reboot
l. Load a file
r. Recover an unbootable HP-UX system
x. Exit to shell

Pick r.

Loading Commands for Recovery
DEVICE FILE SPECIFICATION MENU
This menu is used to specify the path of the root file system.
When the information is correct, select "a".
INFORMATION TO VERIFY:
Device file used for '/' (ROOT) is (c#t#d#).
The hardware path to disk is (hw_path).

Select one of the following:
a. The above information is correct.
b. WRONG!! The device file used for '/' (ROOT) is incorrect.
m. Return to the HP-UX Recovery Menu.
x. Exit to shell.

Selection: a. (If information is correct).

HP-UX RECOVERY MENU
Select one of the following:
a. Mount the root disk and exit to a shell only.
b. Recover the bootlif/os partition.
c. Replace the kernel on the root file system
d. Both Options: b and c.
v. Read instructions about LVM Recovery (LVM RECOVERY).
m. Return to 'HP-UX Recovery Media Main Menu'.
x. Exit to shell.

Select a.
FILE SYSTEM CHECK MENU
The file system check '/sbin/fs/vxfs/fsck -y /dev/rdsk/(c#t#d#) will now be run.

Select one of the following:
a. Run fsck -y.
b. Prompt for the fsck run string on (c#t#d#s1lvm).
m. Return to the 'HP-UX Recovery Menu'.
Selection: a.
(Output of fsck)
Going to mount /dev/dsk/
file system clean - log replay is not required.
Mount /ROOT file system.
/sbin/fs/vxfs/mount /dev/dsk/ /ROOT.
Mount /ROOT/stand again.
/sbin/fs/hfs/mount -F hfs /dev/dsk/ /ROOT/stand.
The root disk has been mounted under /ROOT, if you want to chroot to this
directory type the commands:
loadfile chroot
chroot /ROOT /sbin/sh
# loadfile chroot
# chroot /ROOT /sbin/sh
# vgchange -a y vg00
# mount -a (to mount all the file systems).

Otherwise, to just boot in single-user it is:

hpux -is

or

hpux -is /stand/vmunix

or, if your kernel is corrupt,

hpux -is /stand/vmunix.prev