Hello malefik,
"Yes, I see a lot of objects."
What do they consist of? e.g. snapshots, clones, VMs/vmdks that were scheduled for removal but not removed? Do they reside in healthy accessible namespace folders (and if so, are they the only things in these folders)? If they are then deletion via the GUI (Datastore browser) or PowerCLI could be a cleanup option that shouldn't take a huge amount of time. Are they all VMs that View has recreated? I vaguely recall at some point seeing some method of helping View to clean them up from that side.
"Can I somehow automate the process of deleting these objects?"
If they are healthy and accessible then no, not really - if you can make a (formatted) list it is fairly trivial to make a script to do this but scripting deletion of anything (on vSAN or otherwise) is not a great idea (as there is no 'undo' button). If one were to go this path then do it explicitly (e.g. not using a 'for' loop) with a line for each deletion and obviously one should only be working against this list once they are 100% certain all Objects are safe to delete.
"And also: how can I completely clear the vSAN datastore from the data (format)? its possible easy and fast?"
This depends on the data and your external storage availability/capabilities (another vSAN or SAN/NAS); e.g. a cluster full of non-static applications, file-servers and databases would likely need to be fully moved off and back or backed-up + restored, while on the opposite end of the spectrum, a VDI cluster with temporary instant-clones with no/little persistent data may just be a case of moving off the Golden-images, any persistent customer data, wiping down the cluster and re-provisioning the pools.
Bob
