Preparing compute nodes for eessi

Credit to: https://linuxconfig.org/how-to-create-loop-devices-on-linux

To use eessi on diskless compute nodes, we need to create “pseudo” disk using

• dd for creating an empty file, the size of the disk we need.
• losetup
• parted
• mkfs.ext4
• mount

Create file

dd if=/dev/zero of=loopdevice bs=1M count=32768

Map the file to a block device

• sudo losetup -f # determine the next available block device
• sudo losetup -f loopdevice # map the file called loopdevice to the next available block device

Create a partition and filesystem

• sudo parted -s /dev/loop0 mklabel msdos
• sudo parted -s /dev/loop0 mkpart primary 0% 100%
• `sudo mkfs.ext4 /dev/loop0p1

Mount the file as a drive

• sudo mount /dev/loop0 /cvmfs