Chapter 29 Troubleshooting Miscellaneous Software Problems (Tasks)

This chapter describes miscellaneous software problems that may occur occasionally and are relatively easy to fix. Troubleshooting miscellaneous software problems includes solving problems that aren't related to a specific software application or topic, such as unsuccessful reboots and full file systems. Resolving these problems are described in the following sections.

This is a list of the information in this chapter.

• What to Do If Rebooting Fails

• What to Do if a System Hangs

• What to Do if a File System Fills Up

• What to Do if File ACLs Are Lost After Copy or Restore

• Troubleshooting Backup Problems

What to Do If Rebooting Fails

If the system does not reboot completely, or if it reboots and then crashes again, there may be a software or hardware problem that is preventing the system from booting successfully.

If none of the above suggestions solve the problem, contact your local service provider.

SPARC: Troubleshooting 64–bit Solaris Boot Problems

After the 64–bit Solaris release is installed on an UltraSPARC system, the 64–bit kernel will be booted automatically unless any of the following conditions are true:

• A FLASH PROM upgrade might be required on an UltraSPARC system before it can successfully boot the 64–bit kernel. Refer to your hardware manufacturer's documentation to determine whether your UltraSPARC system requires a firmware upgrade.

• The Open Boot PROM boot-file parameter is set to kernel/unix. If booting the 64–bit kernel fails and this parameter is set, unset it, and reboot the system.

• On some UltraSPARC systems, the 64-bit Solaris kernel is not booted by default, even when the system is completely installed with all the 64-bit Solaris components and the correct firmware is installed. Without booting the 64-bit Solaris kernel, 64-bit applications are unable to run.

  To find out more about this issue, and how to enable booting the 64-bit Solaris kernel by default, see boot(1M).

  You can always discover which Solaris kernel the system is currently running by using the isainfo -kv command.

  $ isainfo -kv 64-bit sparcv9 kernel modules

  This output means the system is running the 64–bit Solaris kernel.

You cannot boot the 64-bit Solaris operating environment on a 32-bit Solaris system.

What to Do if You Forgot Root Password

If you forget the root password and you cannot log into the system, you will have to:

• Stop the system by using the keyboard stop sequence.

• Boot from a boot or install server or from a local CD-ROM.

• Mount the root (/) file system.

• Remove the root password from the /etc/shadow file.

• Reboot the system.

• Log in and set root's password.

This procedure is fully described in “SPARC: Booting a System” in System Administration Guide: Basic Administration and “IA: Booting a System” in System Administration Guide: Basic Administration.

The following examples describe how to recover from a forgotten root password on both SPARC and x86 systems.

SPARC: Example—What to Do 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.

(Use keyboard abort sequence--Press Stop A keys to stop the system)
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

x86: Example—What to Do if You Forgot Root Password

The following example shows how to recover when you forget root's 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.

(Use keyboard abort sequence to stop the system
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

What to Do if a System Hangs

A system can freeze or hang rather than crash completely if some software process is stuck. Follow these steps to recover from a hung system.

1. Determine whether the system is running a window environment and follow these suggestions. If these suggestions don't solve the problem, go to step 2.

   • Make sure the pointer is in the window where you are typing the commands

   • Press Control-q in case the user accidentally pressed Control-s, which freezes the screen. Control-s freezes only the window, not the entire screen. If a window is frozen, try using another window.

   • If possible, log in remotely from another system on the network. Use the pgrep command to look for the hung process. If it looks like the window system is hung, identify the process and kill it.

2. Press Control-\ to force a “quit” in the running program and (probably) write out a core file.

3. Press Control-c to interrupt the program that might be running.

4. Log in remotely and attempt to identify and kill the process that is hanging the system.

5. Log in remotely, become superuser and reboot the system.

6. If the system still does not respond, force a crash dump and reboot. For information on forcing a crash dump and booting, see “SPARC: Forcing a Crash Dump and Rebooting the System” in System Administration Guide: Basic Administration or “IA: Forcing a Crash Dump and Rebooting the System” in System Administration Guide: Basic Administration.

7. If the system still does not respond, turn the power off, wait a minute or so, then turn the power back on.

8. If you cannot get the system to respond at all, contact your local service provider for help.

What to Do if a File System Fills Up

When the root (/) file system or any other file system fills up, you will see the following message in the console window:

.... file system full

There are several reasons why a file system fills up. The following sections describe several scenarios for recovering from a full file system. For information on routinely cleaning out old and unused files to prevent full file systems, see Chapter 16, Managing Disk Use (Tasks).

File System Fills Up Because a Large File or Directory Was Created

A TMPFS File System is Full Because the System Ran Out of Memory

What to Do if File ACLs Are Lost After Copy or Restore

Troubleshooting Backup Problems

This section describes some basic troubleshooting techniques to use when backing up and restoring data.

The root (/) File System Fills Up After You Back Up a File System

You back up a file system, and the root (/) file system fills up. Nothing is written to the media, and the ufsdump command prompts you to insert the second volume of media.

Make Sure the Backup and Restore Commands Match

You can only use the ufsrestore command to restore files backed up with the ufsdump command. If you back up with the tar command, restore with the tar command. If you use the ufsrestore command to restore a tape that was written with another command, an error message tells you that the tape is not in ufsdump format.

Check to Make Sure You Have the Right Current Directory

It is easy to restore files to the wrong location. Because the ufsdump command always copies files with full path names relative to the root of the file system, you should usually change to the root directory of the file system before running the ufsrestore command. If you change to a lower-level directory, after you restore the files you will see a complete file tree created under that directory.

Interactive Commands

When you use the interactive command, a ufsrestore> prompt is displayed, as shown in this example:

# ufsrestore ivf /dev/rmt/0
Verify volume and initialize maps
Media block size is 126
Dump   date: Thu Aug 30 10:13:46 2003
Dumped from: the epoch
Level 0 dump of /export/home on starbug:/dev/dsk/c0t0d0s7
Label: none
Extract directories from tape
Initialize symbol table.
ufsrestore > 

At the ufsrestore> prompt, you can use the commands listed on “UFS Backup and Restore Commands (Reference)” in System Administration Guide: Basic Administration to find files, create a list of files to be restored, and restore them.