I like to determine a fixed size for Read-Cache and and fixed size for Write-Cache individually per drive or in other word "no-shared R/W-strategy".
Is it possible?
Well no-shared R/W strategy isn't exactly the same. When seperating the R/W-cache it would be a good idea to still make Read-cache access the data of Write-cache

I mean with seperation, that i can limit write-size of cache individually to not interfer the read-cache data during big-writes-caching.