PARSEC Technical Information

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====== Troubleshooting a Hanging Init Script in Solaris 8 =====

Solaris 8 boot scripts (''/etc/rc?.d/*'') can hang indefinitely with almost no feedback. Below are the methods that actually work on real Solaris 8 systems.

===== 1. Boot to Single-User Mode from OpenBoot (most reliable) =====

From the ''ok'' prompt:
  ok boot -s

You land at the root shell (#) without most rc-scripts are **not** executed yet.

Now manually test the suspect script with full visibility:

<code>
# sh -v /etc/rc3.d/SxxProblemScript
</code>
or with tracing:
<code>
# sh -x /etc/rc3.d/SxxProblemScript 2>&1 | tee /tmp/debug.out
</code>

===== 2. Force init to Drop into a Shell Early (Solaris 8 trick) =====

In single-user mode edit ''/etc/inittab'' and temporarily replace the initdefault line:

<code>
is:3:initdefault:
</code>

with

<code>
is:3:wait:/sbin/sh < /dev/console > /dev/console 2>&1
</code>

Reboot. init will stop after parsing inittab and give you a shell **before** any rc scripts run.

Then manually execute them one by one:

<code>
# for i in /etc/rcS.d/S*; do echo "=== $i ==="; sh -x $i start; done
# for i in /etc/rc2.d/S*; do echo "=== $i ==="; sh -x $i start; done
# for i in /etc/rc3.d/S*; do echo "=== $i ==="; sh -x $i start; done
</code>

When one hangs, Ctrl-C and debug it.

===== 3. Add Logging to the Offending Script (quick & dirty) =====

In single-user mode edit the suspect script and put at the very top:

<code>
exec > /tmp/SxxScript.log 2>&1
set -x
echo "=== Started at $(date) ==="
</code>

Reboot normally. When it hangs again, boot ''boot -s'', mount root if needed, and read ''/tmp/SxxScript.log'' – it shows exactly where it stopped.

===== 4. Most Common Culprits on Solaris 8 =====

  * NIS/ypbind hanging because master/slave is unreachable (''ypwhich'' hangs)
  * NFS mounts in ''/etc/vfstab'' without ''bg,intr,soft'' when server is down
  * ''route add default ...'' when gateway is unreachable
  * ''/etc/rcS.d/S92volmgt'' starting ''vold'' (waits forever if RPC is broken)
  * ''S69inet'' starting ''in.routed'' or ''in.rdisc''
  * ''keyserv'', ''automount'', or anything waiting for NIS
  * Old Sun Cluster scripts accidentally left enabled

===== 5. Boot from CD as Last Resort =====

  * Boot Solaris 8 CD → single-user
  * Mount root disk under ''/a'' (usually ''/dev/dsk/c0t0d0s0'')
  * Rename or edit the bad script under ''/a/etc/rc?.d/''

===== 6. Quick Checklist Once You Have a Shell =====

<code>
# ps -ef | grep -vE "ps|grep"
# tail -50 /var/adm/messages
# grep yp /var/adm/messages
# ypwhich                     # hangs? → NIS problem
# mount -p                    # anything stuck?
# netstat -rn                 # default route present?
</code>

**99 % of Solaris 8 boot hangs are either NIS/ypbind or an NFS mount without proper timeout options.**