Patch-ID#  100259-01
Keywords: 4.1.1 ufs_inactive syncip nfs performance attachment vmstat
Synopsis: SunOS 4.1.1: ufs_inactive patch
Date: 02/Apr/91

SunOS RELEASE: 4.1.1

Topic: UFS patch

BugID's fixed with this patch: 1054999 

Architectures for which this patch is available: sun3, sun3x, sun4, sun4c

Obsolete By: SysVR4

Problem Description:

BUGID: 1054999


On a 4/490 server, an NFS client is performing a large file copy operation.
After a few minutes, the server slows down and the LED's on the back move
very slowly.  It may take minutes to execute any command.  Running vmstat
during the copy shows a sudden increase in the page attach rate and the
CPU utilization hits 100%.

NOTE:

A side effect of this patch is that the modification time (on disk) of the file
on the server gets updated twice.  First when the file is closed or written
into by the client and second, when the modified pages associated with this file
are written back to disk on the server.  This is due to the fact that modified
pages are not written back to disk on every write from the client if the
server has sufficient free memory.  Thus, when any modified page belonging to
this file is pushed out on the server (e.g., by the pageout daemon), the
modification time on the file is changed.
Having file modification times updated twice may cause specific
applications to fail to write to their files, if that application
believes, as a result of this patch, that its file has been changed .

INSTALL:

As root:
 # mv /sys/sun{3,3x,4,4c}/OBJ/ufs_inode.o /sys/sun{3,3x,4,4c}/OBJ/ufs_inode.o.save

# cp sun{3,3x,4,4c}/ufs_inode.o /sys/sun{3,3x,4,4c}/OBJ/ufs_inode.o

A New kernel will need to be made and installed.
Please refer to the system and networking administration manual
for details on building and installing a new kernel