I can confirm that the contents in the /scratch/vsantraces is not related to VMware vSAN. IMO, I think it stores some kind of log files and should be safe to delete.
Hope this helps.
It has been quite a long time since you posted the question.
I also faced the same issue.
the vsantraces folder will not allow you to dismount/delete the datastore
Use /etc/init.d/vsantraced stop on esxi host which have access to datastore, once done, dismount and delete the datastore
more info available on the links above.
Hate to bring up an old thread as well but I've run into this issue a few times now. We are running ESXi 5.5 U2 and this problem seems to have appeared after applying some security patches (or at least I didn't notice it until then). The process mentioned in the VMware KB works however I've been afraid to disable the service all together as I'm not sure why it's running in the first place. We also do NOT use VSAN. Does anyone know why this is enabled?
I'm having this issue on vSphere 6.0 Update 3, so it's not solved in any updates mentioned in the KB.
I think our hosts never run 5.5, but I'm not entirely sure about this. I am, however, sure that this problem prevents me from decommissioning our old iSCSI datastores.. Let me know if you have any tips, I have run the esxcli commands recommended, still need to see if a reboot fixes this (KB didn't mention anything about a reboot).
Ok, so the _correct_ command is this:
esxcli vsan trace set -p /vmfs/volumes/<name>/<path>
And make sure that the entire folder structure exists, after that you can remove the datastore
Oh my God sir! You have saved my day!
It's working!!!! I've been working at this problem for days!
Thank you very much!!!!