Using Single-User Mode

Normally, when the Sun Enterprise server is fully booted, you use the AP command versions located in /usr/sbin. However, if your server comes up in single-user mode because the boot process did not fully complete, you can use the commands in /sbin. The command versions under /sbin do not rely on the AP daemon services (which are not available in single-user mode). If the system enters single-user mode because of a problem related to AP, you may be able to resolve the problem by using the /sbin commands to perform needed AP operations.

Two AP-related problems may cause the system to come up in single-user mode:

• If two paths are supposed to lead to the same disk (according to the AP SSP database) but those paths actually lead to different disks, and if that disk needs to be mounted during the boot process. (This can only happen if you change the physical configuration of the pathgroup without running AP commands to update the database.)

• If an active alternate for a disk turns out to be inaccessible and that disk is required during the boot process. A disk is required during the boot process if it has file systems that are mounted during the boot process (that is, it has entries in the /etc/vsftab file).

These situations arise only with respect to disks, not networks. In either case, you may be able to use the AP commands under /sbin to resolve the problem.