(If you want to wipe the extended partition table, you'll need to know more about the operating system different operating systems do extended partitions in different ways.) The primary partition table within the MBR (so, not talking about GPT here) is located 446 bytes in, so we instruct dd to seek 446 bytes in before writing.Įxtended partitions are generally created by using a primary partition slot to point at the extended partition table, so if we erase the 4 primary partitions, we effectively wipe the extended partition table as well the OS won't be able to find it, so it won't be able to read and interpret it. Here, we tell dd to write 64 blocks (or bytes, because of our bs=1 parameter), since the primary partition table consists of 4 16-byte partition entries, for a total of 64 bytes. However, we need to address things more precisely than that, so we tell dd to use a block size of 1 byte. The default block size may be 512 bytes, 1024 bytes or 4096 bytes, depending on your system. Here, we specify which device we're writing to. Here, we specify that we're reading from /dev/zero, which is a special device which emits NUL bytes-zeros. It's the simplest flexible tool for this job.

This standard command copies bytes from a source and writes them to a destination. dd if=/dev/zero of=/dev/ bs=1 count=64 seek=446 conv=notrunc If we're talking about MBR-style partitions.

Linux wipe disk