Appendix 3: The Loop Device

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later. Once the file system has been created, and a loop device associated

with file, it can be mounted using the following command line:

mount  t ext2 /dev/loop0 /mnt

When this is later unmounted make sure to release the device with the com 

mand losetup  d /dev/loop1. Another alternative is to release the loop device

as soon as the file system creation is complete, and mount the file as in the

previous example with a command like:

mount  t ext2  o loop=/../image.file /mnt

In either case this produces a  file system  mounted on /mnt that has 100 MB

of storage space. Whatever this file system is intended to contain can now be

copied, or untarred, or otherwise created on the new file system.

It should be evident that loop devices are very useful critters. The instal 

lation software makes use of one to perform several sets in the installation

by mounting image files from the CD, instead of requiring a floppy disk to

mount. This is not only faster, but physically easier than the floppy installa 

tion method.