On 08/10/99 15:01:55 you wrote:

On Tue, 10 Aug 1999, Stephen C. Losen wrote:

...

Actually, if you write N data blocks that correspond to the same parity block, you only do N+1 writes for the N blocks.

That is certainly an optimization. In the most basic case you write one block and update the parity block, which is two writes. One can also read all the blocks that add up to the parity block and recheck, but I wonder what that would do to performance.

Given that Netapp's NVRAM allocates writes and then dumps them to disk periodically in stripes, this type of optimization would probably work well with them. Perhaps they do it already. :)

Bruce