Sorry for the pompousness of replying to my reply.
Please understand that QuickCheck checks the files before
the final files are written to disk.
When the RAID screws up, SABnzbd won't know until unrar starts unpacking.
The (I think reasonable) assumption of SABnzbd is that the file system can be relied upon.
I agree with 2), that using RAID for SABnzbd's temporary download folder is probably not a good idea.
You don't need the redundancy and you will only suffer the performance degradation.
But I also think it's quite worrying that SABnzbd cannot write to the RAID reliably.
I mean, all it does is "open file", "write", "write", "write", "close".
How hard is that for the OS (and RAID) to handle?
Does other software suffer from this?
Should SABnzbd do things differently when on a RAID?
Why is that? Aren't RAIDs supposed to be transparent?
You're not the first one with this issue and I would like to know the root cause.