x86: How to Boot a System for Recovery Purposes (System Administration Guide: Basic Administration)

System Administration Guide: Basic Administration

x86: How to Boot a System for Recovery Purposes

Follow these steps to boot the system to repair a critical system resource. The example shows you how to boot from a Solaris Installation CD or from the network, mount the root (/) file system on the disk, and repair the /etc/passwd file.

Substitute the device name of the file system to be repaired for the devicename variable in the following procedure. If you need help with identifying a system's device names, refer to Chapter 30, Accessing Devices (Overview).

Stop the system first by using the system stop key sequence.

Use the stop sequence for your system if you don't know the root password or if you can't log in to the system. For more information, see x86: How to Stop a System for Recovery Purposes.

Boot from the Solaris installation CD or DVD (or from the network) to single-user mode.
1. Insert the Configuration Assistant boot diskette or the installation CD or DVD that you wish to boot from.
2. If the system displays the Type any key to continue prompt, press any key to reboot the system.
  
  You can also use the reset button at this prompt. If the system is shut down, turn the system on with the power switch.
  
  The Solaris Device Configuration Assistant screen is displayed.
3. Press the F2 key (F2_Continue).
  
  Device identification is performed and the Identified Devices screen is displayed.
4. Press the F2 key (F2_Continue).
  
  Bootable drivers are loaded.
  
  The Boot Solaris menu is displayed.
5. Select the CD-ROM drive or network device. Then press the F2 key (F2_Continue).
  
  The Current Boot Parameters menu is displayed.
6. Type b -s at the prompt. Press Enter.
  
  After a few minutes, the single-user mode # prompt is displayed.

Mount the root (/) file system that contains the invalid passwd file.
# mount /dev/dsk/devicename /a

Change to the newly mounted etc directory.
# cd /a/etc

Make the necessary change to the file by using an editor.
# vi filename

Change to the root (/) directory.
# cd /

Unmount the /a directory.
# umount /a

Reboot the system.
# init 6

Verify that the system has booted to run level 3.

The login prompt is displayed when the boot process has finished successfully.
hostname console login:

x86: Example—Booting a System for Recovery Purposes

The following example shows how to repair the /etc/passwd file after booting from a local CD-ROM.

Type any key to continue

SunOS Secondary Boot version 3.00


Solaris Intel Platform Edition Booting System

Running Configuration Assistant...
Autobooting from Boot path: /pci@0,0/pci-ide@7,1/ide@0/cmdk@0,0:a

If the system hardware has changed, or to boot from a different
device, interrupt the autoboot process by pressing ESC.

Press ESCape to interrupt autoboot in 5 seconds.
      .
      .
      .
Boot Solaris

Select one of the identified devices to boot the Solaris kernel and
choose Continue.

To perform optional features, such as modifying the autoboot and property
settings, choose Boot Tasks.

An asterisk (*) indicates the current default boot device.

> To make a selection use the arrow keys, and press Enter to mark it [X].

[ ]  NET : DEC 21142/21143 Fast Ethernet
on Board PCI at Dev 3                                                
[ ]  DISK: (*) Target 0, QUANTUM  FIREBALL1280A
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1
[ ]  DISK: Target 1:ST5660A
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1
[ ]  DISK: Target 0:Maxtor 9 0680D4
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1
[X]  CD  : Target 1:TOSHIBA  CD-ROM XM-5602B  1546
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1

F2_Continue   F3_Back   F4_Boot Tasks   F6_Help
      .
      .
      .
               <<< Current Boot Parameters >>>
Boot path: /pci@0,0/pci-ide@7,1/ide@0/cmdk@0,0:a
Boot args: kernel/unix -r

Select the type of installation you want to perform:

1 Solaris Interactive
2 Custom JumpStart
3 Solaris Web Start
 
Enter the number of your choice followed by <ENTER> the key.

If you enter anything else, or if you wait for 30 seconds,
an interactive installation will be started.

Select type of installation:  b -s
      .
      .
      .
# mount /dev/dsk/c0t0d0s0 /a
      .
      .
      .
# cd /a/etc
# vi passwd
(Remove invalid entry)
# cd /
# umount /a
# init 6

x86: Example—Booting a System if You Forgot Root Password

The following example shows how to recover when you forget the root password by booting from the network. This example assumes that the boot server is already available. Be sure to apply a new root password after the system has rebooted.

Type any key to continue

SunOS Secondary Boot version 3.00


Solaris Intel Platform Edition Booting System

Running Configuration Assistant...
Autobooting from Boot path: /pci@0,0/pci-ide@7,1/ide@0/cmdk@0,0:a

If the system hardware has changed, or to boot from a different
device, interrupt the autoboot process by pressing ESC.

Press ESCape to interrupt autoboot in 5 seconds.
      .
      .
      .
Boot Solaris

Select one of the identified devices to boot the Solaris kernel and
choose Continue.

To perform optional features, such as modifying the autoboot and property
settings, choose Boot Tasks.

An asterisk (*) indicates the current default boot device.

> To make a selection use the arrow keys, and press Enter to mark it [X].

[X]  NET : DEC 21142/21143 Fast Ethernet
on Board PCI at Dev 3                                                
[ ]  DISK: (*) Target 0, QUANTUM  FIREBALL1280A
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1
[ ]  DISK: Target 1:ST5660A
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1
[ ]  DISK: Target 0:Maxtor 9 0680D4
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1
[ ]  CD  : Target 1:TOSHIBA  CD-ROM XM-5602B  1546
on Bus Mastering IDE controller on Board PCI at Dev 7, Func 1

F2_Continue   F3_Back   F4_Boot Tasks   F6_Help
      .
      .
      .
               <<< Current Boot Parameters >>>
Boot path: /pci@0,0/pci-ide@7,1/ide@0/cmdk@0,0:a
Boot args: kernel/unix -r

Select the type of installation you want to perform:

1 Solaris Interactive
2 Custom JumpStart
3 Solaris Web Start

Enter the number of your choice followed by <ENTER> the key.

If you enter anything else, or if you wait for 30 seconds,
an interactive installation will be started.

Select type of installation:  b -s
      .
      .
      .
# mount /dev/dsk/c0t0d0s0 /a
      .
      .
      .
# cd /a/etc
# vi shadow
(Remove root's encrypted password string)
# cd /
# umount /a
# init 6