I am reading the kernel Documentation/md.txt. It explains what md the items in sysfs mean. It refers a few times to "sectors". - Are we talking 512 bytes or the underlying physical disk sector size? - Do all disks in an array need to have the same sector size? Seeing how md can be built over physical disks, partitions, loop mounts and more, I expect that 'sector' is short for '512 bytes' and real disk sector size is not relevant here. Nevertheless, there is md*/queue/hw_sector_size which gives 512. So there are now a few sector sizes (the array and the underlying devices) and the text does not make it clear which is used where. I assume the array cluster size is the one referred to in this document. TIA -- Eyal Lebedinsky (eyal@xxxxxxxxxxxxxx) -- 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