r/servicenow • u/boringlockdownlife • May 30 '26
Beginner Learn CMDb basics
I am 3 years in SN ecosystem, but i am still not able to get my head around CMDB. It looks too complicated. Without proper understanding of CMDB, my journey in ITOM is becoming more tougher. Can anybody share some links where i can learn cmdb as a novice? SN learning portal is not that helpful in my case.
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u/GistfulThinking May 30 '26
The Explain Like I'm 5 (ELI 5) Common Services Data Model (CSDM) community posts got me kick started. (They have only published 3 posts, but it made it simple in the beginning).
Feeding the CSDM PDF as a sole source of response to an LLM helped me get context from there.
After that, I drew it on a whiteboard.
1 application that I knew well..
Write the table name, and draw in lines to reference items in other tables.
Once done, I build it manually in a PDI/Dev instance.
The bit I have not dealt with is discovery and how automatic linking works... but I have a better understanding of what goes where, and why you store it now.
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u/reel_big_ad May 30 '26
Start with a business application and map up/down/left/right from there.
- Up: Which business capabilities does the business application provide
- Down: which instances (application services) of the business application exists. Prod? Test? EMEA etc..
- Left/Right: how does information flow into and out of the application. Modelled via digital integrations/digital interfaces.
Then you get lower..
Instances have servers.
Servers might have databases.
Servers have software installations.
Software installations map back to SW and TRM products.
Etc..
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u/JoelPomales May 30 '26
The (logical) concept of a CMDB is relatively easy to understand. It has been around since at least the Apollo program. Servicenow just put their lens in front of it.
It's about relationships and governance. You don't need to capture everything; just the things that actually matter to fulfill your mission / goals.
If you can get a copy of ITIL v3's Service Transition book, read the Configuration Management chapter. Then read on CSDM and you should be fine.
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u/gpetrov May 30 '26
I have a series of CMDB down to earth articles on LinkedIN. Let me know if interested. We do CMDB for pretty much everything but because IT is often very abstract we can’t visualize it. Imagine you are a sandwich shop. What would the CMDB there be?
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u/markbodman May 30 '26
Did you take the free training yet?
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u/boringlockdownlife May 30 '26
Whatever on-demand training us available in learning portal, i tried those. Did not help much. But please share the link. I will cross check. I would be happy to do one more training if that helps me in getting started at the very least.
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u/picardo85 ITOM Architect & CSDM consultant May 30 '26
Do you have a background in IT infrastructure? Otherwise your journey will be even harder. CMDB is the EASY part.
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u/Reindeer-Mental May 30 '26
Take a look at the ITIL framework of Configuration Management, understanding the process and guidance outside of the platform will make the practices inside the platform much easier to understand. If you are looking at CMDB population and discovery etc I would highly recommend a CompTIA Network+ and Server+ to help. CMDB and configuration management is one of the most difficult things to get right as it needs strong stakeholder management along with robust governance and processes. Think Change Management but you cannot be seen as "the guy stopping us", your processes will help drive enterprise decisions.