How can we increase the amount of scanners to run simultaneously meaning if we apply 8 scanners it only uses 5 as per the subject.
Is this something that can be configured somewhere?
That depends on a lot of factors. First you would need slicing turned on in the option profile; I am assuming you have that if you see multiple scanners in use.
All the scanners need to have the same configuration that are in the same network for the "Load Balance" algorithms to work in Qualys. For example if you have 5 scanners and 4 of them are set to 4GB of memory and 4 CPU and the 5 is set to 8GB memory and 6 CPU all the scans by default will get allocated to the 5th scanner.
Next when you launch the scan you can have the option to use all scanners in Asset Group or Build my list and add all the scanners you want Qualys to be able to use.
Will have to look at that, Im sure its got slicing on. Is this the only thing that is required apart fomr the configurations being the same on all scanners?
Is there any other options that need to be enabled to allow more than 5 scanners to work simultaneously?
That should be it. But if you wanted to say scan 10.1.1.0/24 Qualys may not slice it; I think it does but I do not know when slicing is triggered in terms of IPs/range to scan. You could open a ticket with Qualys on that.
But if you need any assistance let me know and I can dig into my configs and let you know.
Also if you want to "Measure" I wrote some scripts to use the Appliance APIs to measure my performance across my subscription. Qualys does not provide that view yet but I know I submitted a pretty detailed FR on it.
I can generate stuff like below. We do a LOT of single IP scans but I can watch this and tell if my scanners are not balanced. But it does give me some useful data if I start to see too many scans going to one.
Later this year I will deploy more and then I can cross ref. this data with IP telemetry to try and make sure that our assets in North America are not using a scanner across the pond for instance.
Retrieving data ...