AIX

Console access using the serial cable

Some of the AIX machines do not have normal keyboard/monitor/mouse hookups in back. For console access use the serial dongle in the front of the machine, connect it via serial cable to the ancient HP 2392A box. Then follow these steps on the HP box, pressing the keys listed in order:

F4 (to get to remote mode, not enabled by default, just plain weird.)
User-System Key
F8 (Config Keys)
F3 (DataComm)
F2/F3 (to 9600 baud, screaming fast!)

F1 (Save Config)

Now you have console access, good luck.

How to (re)start the LDAP client

root# /usr/sbin/restart-secldapclntd

If that does not work, kill -9 the secldapclntd and run

root# /usr/sbin/start-secldapclntd

Workaround for nis problems that cause LDAP to hang

nmi-0055 got into an unusable state days after each reboot. The fix is to edit the LDAP config to not use nis. See here for further details.

On 2008-07-22 on nmi-0055, saw problems where the load went to ~130 one day after a reboot because of a similar situation. All load, and ~65% of CPU usage, was because of the LDAP daemon. (Verified by killing the daemon and watching the CPU usage and load disappear.) Removed the ‘numberofthread’ line from below to see what happens.

Add the following lines to /etc/security/ldap/ldap.cfg and restart secldapclntd

nsorder: dns, local
numberofthread: 100

AIX system logging

Some notes on debugging I have tried to add to nmi-0055. The load mysteriously skyrockets and we need to find the cause. Assume the ball is in my court to resolve this for now, and rely on reboots if the load on the machine becomes unmanageable.

update 7/21/08: /var/log/everything should contain most everything now, syslog.conf had syntax error (you can’t use .), if you need to separate anything out, verify by killing syslog ands starting with syslogd -d