Hi, i wrote: > > If you have some blank optical medium, then try whether the emitter of > > the read attempt can be discouraged if the drive is perceived as offering > > just one block of 2048 bytes.
Richmond wrote: > I don't know how to do that. Do you mean make a DVD with 1 block of data? Just put in a blank CD-R, CD-RW, DVD-R, DVD+R, or unformatted blank DVD-RW. The size perception will change to VENDOR MODEL SIZE PHY-SEC LOG-SEC HL-DT-ST HL-DT-ST_DVDRAM_GH15F 2048 2048 2048 Pull it out again, and this state will persist until you put in a medium which is readable, or until you reboot. > > There are many motivations to read the start of the device and fewer to > > read its end. One reason to read the end is the GPT backup header, which > > would sit 512 bytes before the end. > > The main GPT header block is at byte 512 of the storage device. > I am not using GPT on any systems. They all have ext4 root partitions. GPT might be used to mark partitions. It is the newer partition table format, which replaced most usages of the old MBR partition table. Whatever, it is not about what you actually use, but what the yet unknown software is looking for. libblkid would check for properties like PARTTYPE, PARTLABEL, or PARTUUID. Therefore it would look for GPT header blocks, regardless whether they are there. Have a nice day :) Thomas
