i now understand what you mean. i saw that async write operation and i do not realize that is what u think write only. so base on the patch, since i already know exactly that one device will never be read. a simpler way might be 1) modify mdadm to allow one device to be configured as write only 2) add a write only flag in device info and check the flag when do read balance. so no need to update the time at all if no persistent bitmap purpose. i saw the 2.4.x kernel raid has write only flag while dropped in 2.6.x. i guess that is for reconstruction. but we can make use of that for this purpose as well. "write only" can be part of the async write or async replication. but i think raid1 code should be able to allow write only to be a standalone feature so others may have their own async write solution. ming On Wed, 2004-11-10 at 10:56, Paul Clements wrote: > Ming Zhang wrote: > > On Wed, 2004-11-10 at 10:05, Paul Clements wrote: > > > >>Ming Zhang wrote: > >> > >> > >>>is there any technical issue that lead not to be implemented? > >> > >>No. In fact, it has been implemented. Both Peter T. Breuer and I have > >>come up with slightly different patches to implement the write only > >>functionality. > >> > > > > can u send me the patch then i can have a look? > > my patches are here: > > http://parisc-linux.org/~jejb/md_bitmap/ > > you're looking for the async write portion of the code, which has the > write-only functionality in it (later patches do not contain that code, > so look at the older ones) > > check the mailing list archives for discussion > > Peter's patch is here: > > http://marc.theaimsgroup.com/?l=linux-raid&m=109238533827986&w=2 > > > -- > Paul - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
