Booting an x86 System

Table 9-1 describes the boot types covered in this chapter.

Table 9-1

Booting the System ...	Is Usually Done ...	See an Example On ...
To run level 3 (multiuser state)	After shutting down the system or performing some system hardware maintenance task. This is the default boot level where all resources are available and users can log into the system.	page 167
To run level S (single-user state)	After performing some system maintenance task such as backing up a file system. At this level only some file systems are mounted and users cannot log into the system.	page 169
Interactively	After making temporary changes to the system file or the kernel for testing purposes. This type of boot allows you to recover easily if there are problems with the system file or kernel by supplying an alternative pathname to these files when prompted. Use the default settings for the other system prompts.	page 171
From local CD-ROM or the network for recovery purposes	To repair an important system file that is preventing the system from booting successfully. This type of boot is also used for installing (or upgrading) a new release of the operating system.	page 174
Using kadb	To troubleshoot system problems by using the kernel debugger and saving core dumps of the operating system.	page 175

The following procedures use the reset button to restart the system. If your system does not have a reset button, use the on/off switch to restart the system. You might be able to press the Control-Alt-Del keys to interrupt system operation, depending upon the state of the system.

· x86: How to Boot a System to Run Level 3 (Multiuser State)

1. Press any key to reboot the system if the system displays the type any key to reboot prompt. Or, use the reset button to restart the system if the system is shut down.

   The Primary Boot Subsystem menu is displayed after a few minutes.

2. Select the Active Solaris slice (Part #2 in the example on page 183) as the boot device from the Primary Boot Subsystem menu. Press Return.

   If you do not make a selection within 30 seconds, the default boot slice is selected automatically. The Secondary Boot Subsystem menu is displayed.

3. Type b to boot the system to run level 3. Press Return. If you do not make a selection within 5 seconds, the system is automatically booted to run level 3.

Verification--Booting a System to Run Level 3 (Multiuser State)

If the system successfully boots to run level 3 the login prompt is displayed.

hostname console login:

Example--Booting a System to Run Level 3 (Multiuser State)

type any key to reboot Please select the partition you wish to boot: 2 Select (b)oot or (i)nterpreter: b . . . venus console login:

· x86: How to Boot a System to Run Level S (Single-User State)

1. Press any key to reboot the system if the system displays the type any key to reboot prompt. Or, use the reset button to restart the system if the system is shutdown.

   The Primary Boot Subsystem menu is displayed after a few minutes.

2. Select the Active Solaris slice (Part #2 in the example on page 183) as the boot device from the Primary Boot Subsystem menu. Press Return.

   If you do not make a selection within 30 seconds, the default boot slice is selected automatically.

   The Secondary Boot Subsystem menu is displayed.

3. Type b -s to boot the system to run level S. Press Return. If you do not make a selection within 5 seconds, the system is automatically booted to run level 3.

4. Type the root password, if prompted.

5. Perform the maintenance task that needed the run level change to s.

6. Press Control-d to bring the system back to run level 3.

Verification--Booting a System to Run Level S (Single-User State)

Use the who -r command to verify the system is at run level S.

Example--Booting a System to Run Level S (Single-User State)

type any key to reboot Please select the partition you wish to boot: 2 Select (b)oot or (i)nterpreter: b -s . . . INIT: SINGLE USER MODE Type Ctrl-d to proceed with normal startup, (or give root password for system maintenance): xxx # who -r . run-level S Aug 4 13:11 S 0 ? Perform some maintenance task # <Press Control-d>

· x86: How to Boot a System Interactively

1. Boot the system interactively.

ok boot -a

2. Answer the system prompts as described in Table 9-2.

Table 9-2

If the System Displays ...	Do the Following ...
type any key to reboot	Press any key to reboot the system, or use the reset button to restart the system. The Primary Boot Subsystem menu is displayed after a few minutes.
The Primary Boot Subsystem menu	Select the Active Solaris slice as the boot device. Press Return. If you do not make a selection within 30 seconds, the default boot slice is selected automatically.
Select (b)oot or (i)nterpreter:	Type b -a and press Return.
Enter filename [kernel/unix]:	Provide the name of another kernel to use for booting and press Return. Or, press Return to use the default kernel (/platform/i86pc/kernel/unix).
Name of system file [etc/system]:	Provide the name of an alternate system file and press Return, or press Return to use the default /etc/system file.
Name of default directory for modules [/platform/i86pc/kernel /kernel /usr/kernel]:	Provide an alternate path for the modules directory and press Return, or press Return to use the default modules directory path.
root filesystem type [ufs]:	Press Return to use the default root file system type: UFS for local disk booting or NFS for diskless clients.
Enter physical name of root device[physical_device_name]:	Provide an alternate device name and press Return, or press Return to use the default physical name of the root device.

Verification--Booting a System Interactively

The system booted interactively if you are prompted to answer the questions listed in Table 9-2.

Example--Booting a System Interactively

In the following example, the default choices (shown in square brackets []) are accepted.

Select (b)oot or (i)nterpreter: b -a (Copyright notice) Enter filename [kernel/unix]:Return Name of system file [/etc/system]:Return Name of default directory for modules [platform/i86pc/kernel /kernel /usr/kernel]:> Return root filesystem type [ufs]: Return Enter physical name of root device [/eisa/dpt@5c88,0/cmdk@0,0:a]: Return Configuring network interfaces: smc0 Hostname: venus (fsck messages) The system is coming up. Please wait (More messages) venus console login:

· x86: How to Boot a System for Recovery Purposes

Recovering from a invalid /etc/passwd file is used as an example of how to boot a system for recovery purposes.

Substitute the device name of the file system to be repaired for the devicename variable identified in the procedures below. If you need help identifying a system's device names, refer to Chapter 26, "Accessing Devices" in System Administration Guide, Volume I.

Follow the instructions below depending on whether you are booting from the Solaris 2.x installation CD or the network.

1. Boot from the Solaris 2.x installation CD (or the network) to single-user mode using steps a-f.

   If you are booting from the network, skip steps a and b.

   a. Insert the Solaris 2.x installation CD into the CD caddy. b. Insert the CD caddy into the CD-ROM drive.

   c. Insert the Solaris boot diskette into the primary diskette drive (DOS drive A).

   d. Press any key to reboot the system if the system displays the type any key to reboot prompt. Or, use the reset button to restart the system if the system is shutdown.

   The Multiple Device Boot Subsystem menu is displayed after a few minutes.

   e. Select the CD-ROM drive or net(work) as the boot device from the Multiple Device Boot menu.

   The Secondary Boot Subsystem menu is displayed.

   f. Type b -s at the Select the type of installation: prompt.

   After a few minutes, the single-user mode # prompt is displayed.

2. Mount the root (/) file system that has the invalid passwd file.

# mount /dev/dsk/devicename /a

3. Change to the newly mounted etc directory.

# cd /a/etc

4. Set the terminal type.

# TERM=AT386 # export TERM

5. Make the necessary change to the passwd file using an editor.

# vi passwd

6. Change to the root (/) directory.

# cd /

7. Unmount the /a directory.

# umount /a

8. Reboot the system.

# init 6

Verification--Booting a System for Recovery Purposes

The procedure is successful if the system successfully boots to run level.

Example--Booting a System for Recovery Purposes

type any key to reboot Enter the boot device code: 11 Select the type of installation: b -s # mount /dev/dsk/rdsk/c0t3d0s0 /a # cd /a/etc # TERM=AT386 # export TERM # vi passwd # cd / # umount /a # init 6

· x86: How to Stop the System for Recovery Purposes

The specific stop key sequence depends on your system type. For example, press the reset button to stop the system. If your system doesn't have a reset button, turn the power off and back on again.

Forcing a Crash Dump and Rebooting the System

Saving core dumps of the operating system is sometimes necessary for troubleshooting purposes. The savecore command is used to enable this feature. It can be turned on automatically by editing the /etc/init.d/sysetup script.

The savecore feature and how to set it up is described in "Managing System Resources" in System Administration Guide, Volume II. This section only describes how to reboot the system if the savecore feature is enabled.

· x86: How to Force a Crash Dump and Reboot the System

1. Press Control-Alt-d.

kadb>

The kadb> prompt is displayed.

2. Type 0:c at the kadb> prompt.

kadb> 0:c

3. Type :c at the kadb> prompt.

kadb> :c

Verification--Forcing a Crash Dump and Rebooting the System

After the crash dump is written to disk, the system will continue to reboot.

Example--Forcing a Crash Dump and Rebooting the System

<Press Control-Alt-d> kadb> 0:c kadb> :c

x86: Troubleshooting System Problems

Problem -- The System is Hung ...	How to Fix the Problem
At run level 2 or 3.	Log in remotely and attempt to identify and kill the process that is hanging the system.
And you can't log in remotely from another	See "x86: How to Stop the System for Recovery Purposes" on
machine to attempt recovery.	page 174.

Problem -- The System Won't Boot Because ... How to Fix the Problem

There is no default boot device. The message	Boot the system using the Solaris boot diskette and select the disk
displayed is:Not a UFS filesystem	from which to boot.
A process or an external event like a power	See "x86: How to Stop the System for Recovery Purposes" on
failure has caused the system to "hang."	page 174.
An important system file like /etc/passwd	See "x86: How to Boot a System for Recovery Purposes" on page 172.

has an invalid entry.