What are the features of creating a Raid-array of block devices, unlike partitions?

I'm going to create a Raid1 array directly on block devices with absolutely no markup of volumes / partitions, even without gpt. Tested, everything works. But in all manuals write about sections.

  • one
    you have two different questions in one, which is not welcome on this site. Ask the second question separately by clicking the button in the upper right corner. - aleksandr barakin

1 answer 1

no features of creation and use. in fact, from the point of view of information placement, the section of a block device is the same block device, only “in miniature”. in fact, it was precisely for this reason that they (the sections) thought about it so that it was possible to create four files on one physical device, and not one. later, four were turned into “three plus a few more” (one section could be made “extended”, that is, containing several more sections within itself), and even later - into “any number” (this is about gpt ).

there are differences for the “surrounding world”: such a block device (most likely) cannot be used as a boot device.

  • Indeed, such a block device cannot be used as a boot device, creating a boot partition or boot sector on such a device destroys (dissynchronizes) the array. Tested by experiment. - PressAnyKey