HP XC System Software Release Notes for Version 3.0

pdsh@n3: n1: ssh exited with exit code 3
pdsh@n3: n2: ssh exited with exit code 3
0 headerinfo Mon Sep 26 15:49:59 EDT 2005
7.7 Benign pdsh Messages
The pdsh command will display the following message if you enter an invalid node name (in
this example, 1166). This message is benign and can be safely ignored:
# pdsh -w 1166 hostname
pdsh@n3: 1166: ssh exited with exit code 255
7.8 Cannot Connect to MySQL Database During Configuration
At times, especially during the initial configuration or reconfiguration of your system, you might
see the following message:
Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock
If you see that message, perform the following steps to restart the database and resolve the
problem:
1. As root on the head node, restart the database:
# service mysqld restart
This command may report that it fails to either stop or restart the MySQL processes. If so,
continue with the remainder of this procedure.
2. Enter the following command to find MySQL processes:
# ps -eaf | grep mysql
Three processes should be listed: grep, mysqld_safe, and mysqld. If you do not see
mysqld_safe and mysqld, proceed to step 4.
3. Use the process ID (PID) of /usr/libexec/mysqld (the number just after the process
owner name) to kill mysqld manually. If the mysqld process is not listed, but there is a
mysqld_safe process, use that PID instead.
# kill mysqld_PID
This process should kill both mysqld and mysqld_safe.
4. Restart the mysqld service:
# service mysqld start
The command you were trying to run should now be able to connect to the database.
7.9 Consider Disabling Attribute Caching on Large-Scale Systems
On large-scale HP XC systems, NFS attribute caching can cause inconsistencies when large
numbers of client nodes are asked to access files that have been updated recently and the attribute
caching data on the client has not expired. Disabling attribute caching eliminates the problem
but may degrade performance for frequent file operations requiring file attribute data.
You can disable attribute caching using the noac mount option on all external NFS mounts.
7.10 Notes About sendmail
On HP XC systems, inbound mail from external connections is blocked by default at the firewall
and is blocked by the DaemonPortOptions option of the sendmail.cf file. If you intend to
receive mail from outside the HP XC system, you must modify these items.
When making modifications to sendmail, HP recommends that you do not modify the .cf
files directly. Rather, modify the .mc files and run them through an M4 processor to create the
.cf files. The M4 processing tools are part of the sendmail-cf RPM, which is not installed by
default. This RPM is available on the HP XC distribution DVD in the extra RPMs directory.
7.7 Benign pdsh Messages 45