Project team, My remaining issues for this project are all centered around the read-modify-write (RMW) proposal of your project. My primary concern is the default state of RMW as an error. My concerns are that an error return by default is inappropriate. I understand the concerns of the project that serious performance concerns may go undetected without the error return by default. Array manufacturers also are subject to this penalty, if the physical I/O is mis-aligned. The default behavior for arrays does not appear to be a fatal error.
An alternate proposal would be a "multi-state" RMW flag. I'd propose a "warning only" mode as the default, and "return error on RMW" and "do not report RMW conditions" as other potential settings. Having this state be a "global" setting would also seem to be overdone. A system-wide setting seems too much, and a "per-disk" setting also seems the wrong granularity. Setting this on a "per disk partition" would seem to be adequate. Having a global that takes precedence over the per partition would also be acceptable, in my opinion. Please consider these issues. -- --------------------------------------------------------------------- Rick Matthews email: Rick.Matthews at sun.com Sun Microsystems, Inc. phone:+1(651) 554-1518 1270 Eagan Industrial Road phone(internal): 54418 Suite 160 fax: +1(651) 554-1540 Eagan, MN 55121-1231 USA main: +1(651) 554-1500 ---------------------------------------------------------------------
