Once a new burst of data arrives on the cache, the cache is empty, transfers nothing and has no I/O in progress.
I've just done a test:
Add 250 GB of files to the cache
Empty cache via mover on array
At the same time as the mover is executing, launch another 250GB burst of writing to the cache.
At the same time, read and write to the array via SMB shares
My aim is to push it to its limits.
Result: no crashes ...
I'm going to do some more tests, more or less light, and I'll keep you informed.