Hello Neil: Sorry for the late reponse (busy at other stuff) > > If I'm interpreting your numbers correctly, it is just an occasional single > write that is slow - not a series of writes during a one second interval that > are each slow. It would help if you could confirm that. > No. "output.txt" interpretation - "max rw": max per-512KB-block write time in one second - "speed": average write throughput in one second "speed" reveals: It is an occasional single write-throughput-per-second is slow > > I don't know where you got 16 from > Sorry, I do the wrong math > > For some reason raid5 sometimes decides that it needs to pre-read the > 'other' block to calculate parity rather than waiting for the other block > to be written > > Verifying using blktrace... (Now I can reproduce the problem on "virtual machine + virtual disk", with kernel 2.6.34) > > I'd be keen to hear about any further discoveries you make. > OK. BTW, can you reproduce the problem and help debug on this ? My debugging process will very slow (not familiar with RAID code) Thanks Eddy -- 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
