I'm guessing things here without checking, but some issues may be:

* pretty sure JNA mlockall() to lock the cassandra memory from swapping is not available https://issues.apache.org/jira/browse/CASSANDRA-1214

* Creating hard links for the snapshots will be different, not sure exactly how different https://github.com/apache/cassandra/blob/cassandra-0.8.6/src/java/org/apache/cassandra/utils/CLibrary.java#L160

* features that try to avoid polluting the os disk cache will not work 

* off heap row cache ??

* You will have a greater chance of finding help on *nix than windows.   

Hope that helps. 

-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton

On 4/10/2011, at 10:31 AM, Bryce Godfrey wrote:

Iím wondering what the consensus is for running a Cassandra cluster on top of Windows boxes?  We are currently running a small 5 node cluster on top of CentOS without problems, so I have no desire to move.  But we are a windows shop, and I have an IT department that is scared of Linux since they donít know how to manage it.

My primary thoughts of why not, was just community support (havenít seen or heard of  anybody else doing it on Windows), performance, and stability.  The last two are mostly guesses by me, but my thoughts was that java on windows just does not perform as well.  We have a very high right load, and are adding about 5 GB a day of data with a 3 month retention.
 
I really donít want to move a stable system onto an unknown just out of fear of the unknown from my IT department, so looking for some ammo.  Thanks J
 
~Bryce