As I have mentioned in previous mails, I have an sata/usb3 adapter which could work in uas mode, and when it does, it has a weird optimal i/o size: Disk /dev/sdb: 74.5 GiB, 80026361856 bytes, 156301488 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 33553920 bytes http://www.linuxquestions.org/questions/linux-newbie-8/how-to-foramt-2tb-external-hard-drive-4175529792/ In the above link, there shows another similar case of an external drive with 4k physical sector. I am not sure if there's anything wrong with the device(s) or the kernel, but anyway I doubt if fdisk should determine alignment with this size. As you can calculate, it may not necessarily be a multiple of the size of physical sectors, or that of common erase block of SSDs (which is not reported anywhere AFAIK). Perhaps this I/O size does matter on alignment for certain cases, but shouldn't physical sector or erase block be at least of higher priority when it comes to alignment? In any case, it would be nice if fdisk can allow customize alignment (like gdisk does), so that users can at least decide how partitions should be aligned in weird cases like this. With that, the long-time deprecated "dos compatibility" might be able to go as well. -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
