Exadata: ILOM hostname change

I am not sure about the root cause of this one but it was very weird finding that an ILOM had a wrong hostname (yes, wrong hostname) -- below the logs from a cell patching pre-requisites session:

cel01: [ERROR] Details:
cel01: ILOM hostname cel01.domain.com must match cel01-ilom.domain.com in /opt/oracle.cellos/cell.conf  : FAILED
cel01: [Info]: Consistency check FAILED

Indeed, the ILOM had the same hostname as the cell which obviously is not what we want:

[root@db01 ~]# ssh cel01-ilom
Password:
Hostname: cel01
-> show /SP hostname
/SP
    Properties:
        hostname = cel01         <===== bad, this is the cell hostname !
->

The cool thing with ILOMs is that we can change this online with no disruption:

-> set /sp hostname=cel01-ilom
Set 'hostname' to 'cel01-ilom'
-> show /SP hostname
/SP
    Properties:
        hostname = cel01-ilom   <===== good
->

One more easy online fix (for a weird issue :))!