Nix wrote: [] > With iflag=direct I get, um, > > loki:/var/log# time dd if=/dev/md1 bs=1000 count=502400 of=/dev/null iflag=direct > dd: reading `/dev/md1': Invalid argument For direct i/o, you have to use blocksize =512, 1024, ... - multiple of a sector size. /mjt - 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