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Network Operating Systems-I

notes Check group disk quota information (-g)
Once quotacheck has finished running, you should see the quota files corresponding to the
enabled quotas (user and/or group) in the root directory of each quota-enabled file system
Now we are ready to begin assigning quotas.

assigning Quotas

The mechanics of assigning disk quotas are relatively simple. The edquota program is used to edit
a user or group quota. The command to manage quotas is “edquota”. The “edquota” command
uses the “-u” qualifier to modify users quotas.

edquota -u damian

Once you have set up a user quota it is the same process for setting up a group quota. The
“edquota” command issued with the “-g” qualifier allows you to modify group quotas

edquota -g users

edquota uses a text editor (which can be selected by setting the EDITOR environment variable to
the full pathname of your preferred editor) to display and change the various settings.

Task Describe the various steps of enabling the disk quotas.

10.2 anatomy of file system

When it comes to file systems, Linux® is the Swiss Army knife of operating systems. Linux
supports a large number of file systems, from journaling to clustering to cryptographic. Linux is
a wonderful platform for using standard and more exotic file systems and also for developing
file systems.
This article explores the virtual file system (VFS)—sometimes called the virtual filesystem
switch—in the Linux kernel and then reviews some of the major structures that tie file systems
together.
The VFS keeps track of the currently-supported file systems, as well as those file systems that are
currently mounted.
vfs
File systems can be dynamically added or removed from Linux using a set of registration
functions. The kernel keeps a list of currently-supported file systems, which can be viewed
from user space through the /proc file system. This virtual file also shows the devices currently
associated with the file systems. To add a new file system to Linux, register_filesystem is called.
This takes a single argument defining the reference to a file system structure (file_system_type),
which defines the name of the file system, a set of attributes, and two superblock functions. A file
system can also be unregistered.
Registering a new file system places the new file system and its pertinent information onto a
file_systems list. This list defines the file systems that can be supported. You can view this list by
typing cat /proc/filesystems at the command line.

180 LoveLy professionaL university