how to delete the partition after mkfs

we created the ext file system on new sdd disk as the follwing

 mkfs.ext4  -j -m 0 /dev/sdd -F

in order to get the disk as was before mkfs

I guess we need to delete the partition that created by mkfs ,

how to perform that ?

Solution 1:

mkfs doesn't create a partition, it creates a filesystem. You created a filesystem on the entire device /dev/sdd (as opposed to a partition e.g. /dev/sdd1).

Your disk is not partitioned, the resulting layout is called superfloppy. If you want to utilize (almost) the whole device to a single filesystem then it's still better to have a partition table with one partition. Compare: Uses of single-partition disk configuration.

Tools like fdisk or gdisk should allow you to create a partition table without any preparations (you will lose data from the current filesystem though, so copy what you want to save). If you create a single partition then you should later run mkfs.ext4 with /dev/sdd1 as a target to create a filesystem on the partition.

If you want to wipe the current filesystem (prior to fdisk/gdisk/whatever or for any other reason) then

• fill the beginning of the disk with zeros, 1MB should be enough:

    dd if=/dev/zero of=/dev/sdd bs=1M count=1
  

• or use wipefs on /dev/sdd; this tool is designed to erase filesystems.