Exercising With Loop Block Devices

• During our demonstration, we will use loop (block) devices, that will serve as our physical volumes.
• To create such a loop device:
  1. Create a large file:

     dd if=/dev/zero of=vdisk1 bs=1m count=1000

  2. Create a loop device on top of this file:

     losetup -f vdisk1

  3. Check that this worked:

       root@simey:~/vdisks# losetup /dev/loop0
       /dev/loop0: [1601]:8388744 (vdisk1)
       root@simey:~/vdisks# dd if=/dev/loop0 of=/dev/null bs=512 count=1
       1+0 records in
       1+0 records out
       512 bytes (512 B) copied, 0.016822 seconds, 30.4 kB/s
       

Originally written by guy keren