I figure out how to enable the write caching without having to run stuff in linix, thank goodness.
To enable write caching on a Dell SAS 5/iR raid controller
Danger: this controller does not have a battery on board to handle cached writes
during an unexpected power outage, that's why they make it hard to set this.
This change makes a massive change in disk performance. I was copying a 135 MB file from one folder to another to test this. Before enabling write caching, it took between 25 and 37 seconds to copy this file. After enabling write caching, it took 5 seconds. In my case, we can risk the potiental corruption in the case of a sudden power outage.
Download LSIUTIL from lsi.com
Click support and downloads. Last file is LSIUtil. Accept their terms and the download commences.
Expand the zip file, run LSIUtil.exe from the windows subfolder.
This opens a dos box.
Select your controller - in my case there was only one. <1 enter>
Select option 21 - RAID actions. <21 enter>
Select option 32 - Change Volume Setting <32 enter>
First prompt is the main one:
Enable write caching: [Yes or No, default is No] <Yes enter>
Offline on SMART Data [Yes or No, default is No] <enter> (leaves default)
Auto configuration: [Yes or No, default is Yes] <enter>
Priority resynch: [Yes or No, default is Yes] <enter>
Hot Spare Pools (bitmask of pool numbers): [00 to FF, default is 01] <enter>
Then <0 enter> your way out of the utility (take 3 of them).
I know it's been two years since the prior post, but hopefully it will save someone the hours of searching I spent coming up with this solution.