Restive Technology

Whenever I migrated a linux server using the VMware Converter, my ethernet devices disappeared. I found a quick and easy way to restore them without any fancy work. Just delete (or move) the file /etc/udev/rules.d/70-persistent-net.rules. This file is used to associate the eth devices with a mac address so that they always come up the same way. When VMware converts a machine, it assigns a different mac address to the virtual ethernet adapter, so this file needs to be deleted.

Thanks to http://techblog.romero.id.au/2009/06/ubuntu-missing-eth0-after-cloning-in-vmware/ for the explanation.

I use Nagios to monitor services. I use a script called check_openmanage to monitor the Dell OpenManage agent on ESX servers using SNMP.  I noticed that it was returning the result

“UNKNOWN: (SNMP) OpenManage is not installed or is not working correctly”

In order to diagnose the problem, I had to connect to the ESX server via SSH.  OpenManage 5.5 runs a few services on the ESX backend.  To check the services, I ran:

/sbin/chkconfig –list |grep dsm

Those services looked fine… so I ran another command for more detail

/sbin/service –status-all |grep dsm

Aha,  dsm_sa_snmp32d was not running.  But I didn’t know the name of the service attached to it.  I found the file:

find / -iname dsm_sa_snmp32d

/opt/dell/srvadmin/dataeng/bin/dsm_sa_snmp32d

OK, I know where that file is… but how does Dell want me to run it?

ls /opt/dell/srvadmin/dataeng/bin

I see “dataeng” as a lone file without an extension.  It is probably the executable that starts the other services.  Sure enough if I ls /etc/init.d I find the same file.

/etc/init.d/dataeng restart

And everything’s working again!

Why did it happen?  Who knows.  It was working fine for months before, so I will just shrug it off as one of those things.  I don’t have time to mess with it any further.