I think the inner-workings of this process is worth looking into the source code to determine whether greenbone-feed-sync places some sort of lock which logically interupts the scan task, and releases it when the feed data has finished populating the database. However, other than a source code review, I don’t know how else you can determine the answer.
After that feed statuses changed from Update in progress... to Current and the new scan started successfully. But now it is interrupted again, Feeds are in Update in progress... and the previous solution doesn’t work anymore. At least new files in /tmp aren’t created near each other. It stuck with creating a temp file, filling it with 1,1 GB of data, deleting it and so on.
8 GB of RAM is also on the low side for running our stack, especially when a feed update and vulnerability scans run in parallel, both of which can be very resource-intensive. See this post for further information. Is it possible to assign more RAM to the VM and see if the problem persists?
I thought that the low side is 4GB as documentation claims. But anyway we doubled RAM. And it looks like 16GB is enough for now to run a scan and update feeds simultaneously. I’ll take a look at it for several days and report back here. Thank you for the help!