I have been working on my NAS that is using server 2012r2 with storage spaces.
- the drives are off the shelf 7200 rpm drives
- the drives are bitlocker encrypted
- the drives are in a 8 disk parity layout
My question is this. Using SMB multichannel I have been able to transfer a 500 MB file in about 2.5 seconds at about 200MB a second to my NAS, but I see that the NAS copies that file to disk over the next 10 seconds. Why does it take that long to copy to disk? Surely 8 disks in a storage space could write more then 20-40MB a second...
The problem comes when I try to write huge files 3+ GB to the server as the transfer speeds will go from 200MB/s down to almost 0 while it writes to disk everything that has been cached.