What kind of skill set that ITOM guy should have to implement CMDB discovery for non-windows devices

[Mihir Y]

There is a need to discovery devices other than Windows like Unix, Linux or whatever applicable. I wanted to know is there any specific skillset required to implement discovery on these devices? Does the person should be aware of Linux, Unix machines configuration? How different is this from Identifying windows machines?

[Hayo Lubbers · Accepted solution]

Hi @Mihir Y ,

Discovery needs to be implemented in consultation with the server owners, in this case the Linux server admins.

It is a desirable that the ITOM person has basic knowledge of the systems that need to be discovered, but you can't expect a platform developer to have in-depth knowledge of all different types of hardware (servers, network, firewalls) and software.

The discovery itself is very similar to the Windows machine discovery. It logs in and executes a bunch of command to retrieve and process the information. The processing of the information is at the same location in the ServiceNow platform.

For the commands that will be executed, have a look at:

https://docs.servicenow.com/bundle/xanadu-it-operations-management/page/product/discovery/reference/...

You will find a list of the attribute that is searched for and with which command it is trying to retrieve this information.

I've made my own little more detailed list a while ago (Paris version), but it probably hasn't changed much.

FieldName	Command / Source	Example	Additional Info
Operating System	uname	Linux	uname.split(/ /)[0]
Host Name	uname -a	VM_UbunutuTest	uname.split(/ /)[1]  + some formatting
OS Version	uname -a or cat /etc/*release	5	uname.split(/ /)[2] or cat /etc/*release | grep -v ID_LIKE Full Version. Release tag, except Ubuntu, there Version tag
Serial number(s)	dmidecode		sudo dmidecode -t 1 | cat >> system_serial && uuid_serial motherboard_serial via sudo dmidecode -t 2 | cat chassis_serial_number via sudo dmidecode -t 3 | cat
Model ID	dmidecode		sudo dmidecode -t 1
Manufacturer	dmidecode	inntotek GmbH	sudo dmidecode -t 1
FQDN	linux_fqdn.sh	vm_ubuntutest.internal.com	-
DNS Domain	DNS, NBT	internal.com	Extracted from FQDN
Kernel Release	uname -r |cut -d'.' -f1	5	Example: uname -r = 5.8.0.53-generic would result in kernel version : 5
IP Address	ifconfig or ip address show	134.27.224.127	IPv4 Kernel version till v3 : ifconfig -a, every inet is stored IPv4 Kernel version > 3 : ip -4 -o addr show IP v6 : ip -6 -o addr show
MAC Address	ifconfig or ip address show
Default Gateway	ip r or route -n	134.27.224.1	Kernel version till v3 : route -n Kernel version >3 : ip r
Disk space (GB)	/proc/ide, /proc/scsi, /var/log/dmesg	550	The value is an aggregation of the disk space for all non-removable disk including both directly attached and SAN storage.
RAM (MB)	cat /proc/meminfo	24,576
CPU Speed (Mhz)	cat /proc/cpuinfo	2,594	cpu Mhz
CPU name	cat /proc/cpuinfo	Intel(R) Xeon(R) CPU E5-2690 v3 @ 2.60GHz	model name
CPU count	cat /proc/cpuinfo	4	physical_id count or 1
CPU core count	cat /proc/cpuinfo	4	cpu cores
Is Virtual	grep hypervisor /proc/cpuinfo	true/false	True for all non physicial servers

Hope this helps,

Hayo

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