DOCUMENT ID:  1513-02

SYNOPSIS:     Why does system hang during shutdown?

OS RELEASE:   Solaris 2.4

PRODUCT:      OS

KEYWORDS:     shutdown init umount umountall


SYMPTOMS:     The shutdown command hangs


DESCRIPTION:

When the shutdown or the init command is given the system does not come
to the OK prompt.  It hangs for a very long time. Why?
 

SOLUTION:

Solaris 2.4 introduced a parallel umount command.  The command umount
-a will try to unmount all the file systems except a few important
ones.  See man page of umount(1m) for more info. 

When you have many file systems to unmount they all try to go in
parallel.  This causes a deadlock for a kernel resource and hence the
hang. 
		      
Workaround:

To solve the problem add the following to the /etc/system file.  Set
ksyms:nksyms_clones = { 30 + the number of file systems that you have}


DATE APPROVED: 09/05/95