SUMMARY: Clients hang when server is rebooted

From: Tom Crummey (
Date: Tue Jan 21 1992 - 20:10:54 CST


Thank you for all the responses. I thought I'd summarize now, even though I have
not yet seen my original query or the apology for the bouncing of mail in my
incoming mail box.

The problem was that diskless clients would hang after the server had been
rebooted until a successful login had been achieved, or the client had also been
rebooted. Many people wrote saying that they have the same problem.

Apparently the problem is due to a bug in the ypbind program and its caching of
the ypserver information and its very long timeout for this cached information.
There is an official SUN patch avaiable which is basically a new ypbind program.
The patch number is 100342-01 and here is the readme:

Date: 1/Aug/1991

SunOS release: 4.1 4.1.1

Unbundled Product:

Unbundled Release:

Topic: NIS rebind patch

BugID'd fixed for this patch: 1046416

Architectures for which this patch is available: sun3, sun4

Patches which may conflict with this patch:

Obsoleted by: Sys_V_Rel4

Problem Description:

  Bug 1046416:

  If you bring a ypserver down into single user and then boot it into
  multi user by either typing control D or reboot, the yp clients
  will take a long time to rebind to the server.

********************* WARNING ******************************

  This is a new version of ypbind that never uses the NIS
  binding file to cache the servers binding. This will have
  the effect of fixing the current symptom. However, it might
  degrade the overall performance of the system when the
  server is available. This is most likely to happen on an
  overloaded server, which will cause the network to produce
  a broadcast storm.



As root and for the correct architecture directory.

#kill the currently running ypbind

kill <processid of ypbind>

mv /usr/etc/ypbind /usr/etc/ypbind.FCS

#copy the new version to /usr/etc

cp sun{3,4}/ypbind /usr/etc

chown root /usr/etc/ypbind
chmod 755 /usr/etc/ypbind

 restart ypbind

I haven't installed this yet, since our network is quite busy and I wasn't
very happy about the warning.

The responses were as follows:

Me Too:

The Patch:

Other Workarounds: sent a script to kill and restart ypbind on the clients if a
lock file written by the NIS server had changed (due to a reboot). If anyone
wants this contact me or him. suggested manually restarting the ypbind process
on each client. suggested using ypwhich <hung client> as the kick to get ypbind
to rebind.

Just Live With It: (well, try a login, wait two minutes and all will

Other Suggested Causes: suggested that another part of the delay could be
due to /usr/ucb/quota. There has been quite a bit of comment lately about quota
causing login delays since it touches all mounted NFS filesystems and if some
NFS servers are away, login cannot complete. He suggests linking /usr/ucb/quota
to /bin/true if quotas are not needed. This will speed up normal logins as well.

If anyone wants further details of any of the mail I received, please mail.
If you want the patch, if you have SUN support, they can email the patch
to you. That is where I got it. I have not seen it on any archives. If you do
not have support, I will mail the patch to you.


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