These are CMMDS entries not DOM-Objects and thus it is completely expected behaviour to not be able to remove these using objtool.
These can be removed using cmmds-tool delete option but I must emphasise that extreme caution must be applied when doing such things (e.g. don't delete entries for any host or any entry belonging to it that has any possibility of coming back, don't even consider using this for removing any entries relating to DOM or LSOM-Objects as they won't remove the data just remove the CMMDS describing them etc.).
Thank you TheBobkin!
I've used cmmds-tool to remove this object (it was a disk group from an unavailable old server) and the error gone.
Also, there are some CMMDS entries with unhealty status. For example, hosts that I had removed previously. Those hosts will never come back and they are not present in the cluster or in the vcenter infrastacture at all. TheBobkin What do you think, should I remove it via cmmds-tool or leave it as it is?
Happy to help.
I must repeat though for anyone who happens across this post in future - please don't go messing with cmmds-tool unless you know what you are doing and the problem is clear, if in doubt then please just call us at GSS.
Unhealthy references to old nodes can be fairly common as a result of nodes getting re-imaged following boot device failure etc. - You can remove them if you like but the only time I have seen these cause any type of issues is if they are related to Witnesses (which have extra entry types such as PREFERRED_FAULT_DOMAIN etc.), I have yet to encounter any negative impact of leftover normal NODE references.