The command “hmc rmsysconn” removes the connection of an HMC to a managed system. The command should only be used for managed systems with static IP.

Before removing the connection to a managed system, the status of the connection should first be determined. This can be done with the command “hmc lssysconn“:

$ hmc lssysconn hmc01
                             RESOURCE                                   
MTMS              STATE      TYPE      IPADDR          ALT_IPADDR   SP       SP_TYPE  SP_PHYS_LOC
…
9105-22B*8CB3552  Connected  sys       192.168.240.12  unavailable  -        ebmc     -
…
$

When removing a connection, either the IP address:

$ hmc rmsysconn hmc01 192.168.240.12
$

or the managed system (via name, serial number, MTMS, …) must be specified:

$ hmc rmsysconn hmc01 ms11
$

The LPAR tool’s database is automatically updated accordingly. A run of “hmc rescan” should not be necessary.

If a managed system that uses DHCP is removed with “hmc rmsysconn“, not only is the connection removed, but the IP address of the managed system obtained via DHCP is added to the list of manually removed IP addresses. Managed systems with such an IP address are no longer automatically recognized by the HMC. However, IP addresses can be removed from this list using “hmc rediscoversysconn” or “hmc mksysconn“.