Task |
Description |
For Instructions |
---|---|---|
Stop a system for recovery purposes. |
If a damaged file is preventing the system from booting normally, first stop the system to attempt recovery | |
Force a crash dump of and reboot of the system. |
You can force a crash dump and reboot of the system as a troubleshooting measure. | |
Boot a SPARC based system for recovery purposes. |
Boot to repair an important system file that is preventing the system from booting successfully. | |
Boot a system with the kernel debugger. |
You can the system with the kernel debugger to troubleshoot booting problems. Use the kmdb command to boot the system. |
SPARC: How to Boot the System With the Kernel Debugger (kmdb) |
You might need to use one or more of the following methods to troubleshoot problems that prevent the system from booting successfully.
Troubleshoot error messages when the system boots.
Stop the system to attempt recovery.
Boot a system for recovery purposes.
Force a crash dump and reboot of the system.
Boot the system with the kernel debugger by using the kmdb command.
Type the Stop key sequence for your system.
The monitor displays the ok PROM prompt.
ok |
The specific Stop key sequence depends on your keyboard type. For example, you can press Stop-A or L1-A. On terminals, press the Break key.
Synchronize the file systems.
ok sync |
When you see the syncing file systems... message, press the Stop key sequence again.
Type the appropriate boot command to start the boot process.
For more information, see the boot(1M) man page.
Verify that the system was booted to the specified run level.
# who -r . run-level s May 2 07:39 3 0 S |
Press Stop-A ok sync syncing file systems... Press Stop-A ok boot |
Forcing a crash dump and reboot of the system are sometimes necessary for troubleshooting purposes. The savecore feature is enabled by default.
For more information about system crash dumps, see Chapter 17, Managing System Crash Information (Tasks), in System Administration Guide: Advanced Administration.
Use this procedure to force a crash dump of the system. The example that follows this procedure shows how to use the halt -d command to force a crash dump of the system. You will need to manually reboot the system after running this command.
Type the stop key sequence for your system.
The specific stop key sequence depends on your keyboard type. For example, you can press Stop-A or L1-A. On terminals, press the Break key.
The PROM displays the ok prompt.
Synchronize the file systems and write the crash dump.
> n ok sync |
After the crash dump is written to disk, the system will continue to reboot.
Verify the system boots to run level 3.
The login prompt is displayed when the boot process has finished successfully.
hostname console login: |
This example shows how to force a crash dump and reboot of the system jupiter by using the halt -d and boot command. Use this method to force a crash dump and reboot of the system.
# halt -d Jul 21 14:13:37 jupiter halt: halted by root panic[cpu0]/thread=30001193b20: forced crash dump initiated at user request 000002a1008f7860 genunix:kadmin+438 (b4, 0, 0, 0, 5, 0) %l0-3: 0000000000000000 0000000000000000 0000000000000004 0000000000000004 %l4-7: 00000000000003cc 0000000000000010 0000000000000004 0000000000000004 000002a1008f7920 genunix:uadmin+110 (5, 0, 0, 6d7000, ff00, 4) %l0-3: 0000030002216938 0000000000000000 0000000000000001 0000004237922872 %l4-7: 000000423791e770 0000000000004102 0000030000449308 0000000000000005 syncing file systems... 1 1 done dumping to /dev/dsk/c0t0d0s1, offset 107413504, content: kernel 100% done: 5339 pages dumped, compression ratio 2.68, dump succeeded Program terminated ok boot Resetting ... Sun Ultra 5/10 UPA/PCI (UltraSPARC-IIi 333MHz), No Keyboard OpenBoot 3.15, 128 MB memory installed, Serial #10933339. Ethernet address 8:0:20:a6:d4:5b, Host ID: 80a6d45b. Rebooting with command: boot Boot device: /pci@1f,0/pci@1,1/ide@3/disk@0,0:a File and args: kernel/sparcv9/unix SunOS Release 5.10 Version s10_60 64-bit Copyright 1983-2004 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. configuring IPv4 interfaces: hme0. add net default: gateway 172.20.27.248 Hostname: jupiter The system is coming up. Please wait. NIS domain name is example.com . . . System dump time: Wed Jul 21 14:13:41 2004 Jul 21 14:15:23 jupiter savecore: saving system crash dump in /var/crash/jupiter/*.0 Constructing namelist /var/crash/jupiter/unix.0 Constructing corefile /var/crash/jupiter/vmcore.0 100% done: 5339 of 5339 pages saved Starting Sun(TM) Web Console Version 2.1-dev... . . . |
Use this procedure when an important file, such as /etc/passwd, has an invalid entry and causes the boot process to fail.
Use the stop sequence described in this procedure if you do not know the root password or if you can't log in to the system. For more information, see SPARC: How to Stop the System for Recovery Purposes.
Substitute the device name of the file system to be repaired for the device-name variable in the following procedure. If you need help identifying a system's device names, refer to Displaying Device Configuration Information in System Administration Guide: Devices and File Systems.
Stop the system by using the system's Stop key sequence.
Boot the system in single-user mode.
Mount the file system that contains the file with an invalid entry.
# mount /dev/dsk/device-name /a |
Change to the newly mounted file system.
# cd /a/file-system |
Set the terminal type.
# TERM=sun # export TERM |
Remove the invalid entry from 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 booted to run level 3.
The login prompt is displayed when the boot process has finished successfully.
hostname console login: |
The following example shows how to repair an important system file (in this case, /etc/passwd) after booting from a local CD-ROM.
ok boot cdrom -s # mount /dev/dsk/c0t3d0s0 /a # cd /a/etc # TERM=vt100 # export TERM # vi passwd (Remove invalid entry) # cd / # umount /a # init 6 |
The following example shows how to boot the system from the network when you have forgotten the root password. This example assumes that the network boot server is already available. Be sure to apply a new root password after the system has rebooted.
ok boot net -s # mount /dev/dsk/c0t3d0s0 /a # cd /a/etc # TERM=vt100 # export TERM # vi shadow (Remove root's encrypted password string) # cd / # umount /a # init 6 |
This procedure shows you the basics for loading the kernel debugger (kmdb). For more detailed information, see the Solaris Modular Debugger Guide.
Use the reboot and halt command with the -d option if you do not have time to debug the system interactively. To run the halt command with the -d option requires a manual reboot of the system afterwards. Whereas, if you use the reboot command, the system boots automatically. See the reboot(1M) for more information.
Halt the system, causing it to display the ok prompt.
To halt the system gracefully, use the /usr/sbin/halt command.
Type either boot kmdb or boot -k to request the loading of the kernel debugger. Press return.
Enter the kernel debugger.
The method used to enter the debugger is dependent upon the type of console that is used to access the system:
If a locally attached keyboard is being used, press Stop-A or L1–A, depending upon the type of keyboard.
If a serial console is being used, send a break by using the method that is appropriate for the type of serial console that is being used.
A welcome message is displayed when you enter the kernel debugger for the first time.
Rebooting with command: kadb Boot device: /iommu/sbus/espdma@4,800000/esp@4,8800000/sd@3,0 . . . |
ok boot kmdb Resetting... Executing last command: boot kmdb -d Boot device: /pci@1f,0/ide@d/disk@0,0:a File and args: kmdb -d Loading kmdb... |