AIX > Administrator > Systems Management

How to Diagnose RMC Connection Issues From the HMC


 


Back February 2011, I wrote about troubleshooting and resolving (Dynamic Logical Partition) DLPAR issues on my blog. One detailed post (see here) was on how to diagnose a DLPAR problem, what some of the most common problems are and how to fix them.

It is one of the most viewed posts on my blog, so it's good to know that the DLPAR article has helped others. With that in mind, I wanted to share some additional information in this area. Starting with HMC Version 8 Release 8.1.0, a new command was introduced to assist Power Systems administrators in troubleshooting and resolving RMC issues on the HMC. The release states: 


"The diagrmc command has been added to check the HMC for possible problems that can prevent the HMC from establishing RMC connections to partitions."


While this utility has been available on the HMC, it wasn’t widely known or used by administrators. The official documentation for the command can be found here. 

I find the two most useful ways to use this tool are with the following options:

diagrmc --autocorrect -v
diagrmc -m managed-system –id --ip partition-IP-address --autocorrect -v

The first command will provide a simple overview and status check of the RMC subsystem on the HMC. The second command will verify RMC connectivity from the HMC to a specific LPAR and IP address. The --autocorrect option will attempt to (as the name implies) automatically correct any RMC connection issues on the HMC, without manual intervention.

In the example that follows, I’ll use the diagrmc command to view the RMC status on the HMC (no issues are reported).

hscroot@hmc1:~> diagrmc
** Checking management console network setup,
 NIST mode, firewall, RMCkey, etc.:
	-- The management console does not 
have a name server defined to 
resolve partition host names.

** Checking RMC subsystem:

** Checking duplicate IPs:
	-- No duplicate IP address found.

** Checking duplicate NodeIDs:
	-- No duplicate NodeID found.

I’ll run the command again, this time with the autocorrect (and verbose) options. Again, no issues are found. See Figure 1.

The next example will check the RMC connection to a specific AIX LPAR. Note that I need the name of the managed system before I can start the command. After I’ve found the name of the managed system, I use the diagrmc to check the RMC connection between the HMC and LPAR id 101 (and IP address 10.2.55.225). You'll notice that I'm using the framels command (alias) below to get the managed system name. This alias can be found in the EZH HMC scripts, written by Brian Smith. If you haven't already installed this on your HMC, I highly recommend it, as it helps simplify administration tasks on your HMC.

http://ezh.sourceforge.net/?cm_mc_uid=45790754817414781421707&cm_mc_sid_50200000=1478565880
hscroot@hmc1:~> source ezh
hscroot@hmc1:~> framels
Running:  lssyscfg -r sys -F name
Server-8286-42A-SN214F55V

hscroot@hmc1:~> diagrmc -m Server-8286-42A-SN214F55V --id 101 --ip 
10.2.55.225

** Checking management console network setup, 
NIST mode, firewall, RMCkey, etc.:
	-- The management console does not have a name server defined to resolve 
partition host names.

** Checking RMC subsystem:

** Checking duplicate IPs:
	-- No duplicate IP address found.

** Checking duplicate NodeIDs:
	-- No duplicate NodeID found.

** Checking ID, network, etc. for partition 101*8286-42A*214F55V 
10.2.55.225:

** Testing network connectivity.
	-- Lpar 101*8286-42A*214F55V/10.2.55.225 has RMC connection.

Chris Gibson is an AIX and PowerVM specialist located in Melbourne, Australia. He is an IBM Champion for Power Systems, IBM CATE (Power Systems and AIX), and a co-author of several IBM Redbooks publications.



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