The first way to manage your partition space is with the df (disk free) command. The command df -k (disk free) displays the disk space usage in kilobytes, as shown below −
$df -k Filesystem 1K-blocks Used Available Use% Mounted on /dev/vzfs 10485760 7836644 2649116 75% / /devices 0 0 0 0% /devices $
Some of the directories, such as /devices, shows 0 in the kbytes, used, and avail columns as well as 0% for capacity. These are special (or virtual) file systems, and although they reside on the disk under /, by themselves they do not consume disk space.
The df -k output is generally the same on all Unix systems. Here’s what it usually includes −
|Sr.No.||Column & Description|
The physical file system name
Total kilobytes of space available on the storage medium
Total kilobytes of space used (by files)
Total kilobytes available for use
Percentage of total space used by files
What the file system is mounted on
You can use the -h (human readable) option to display the output in a format that shows the size in easier-to-understand notation.
The du (disk usage) command enables you to specify directories to show disk space usage on a particular directory.
This command is helpful if you want to determine how much space a particular directory is taking. The following command displays number of blocks consumed by each directory. A single block may take either 512 Bytes or 1 Kilo Byte depending on your system.
$du /etc 10 /etc/cron.d 126 /etc/default 6 /etc/dfs ... $
The -h option makes the output easier to comprehend −
$du -h /etc 5k /etc/cron.d 63k /etc/default 3k /etc/dfs ... $
A file system must be mounted in order to be usable by the system. To see what is currently mounted (available for use) on your system, use the following command −
$ mount /dev/vzfs on / type reiserfs (rw,usrquota,grpquota) proc on /proc type proc (rw,nodiratime) devpts on /dev/pts type devpts (rw) $
The /mnt directory, by the Unix convention, is where temporary mounts (such as CDROM drives, remote network drives, and floppy drives) are located. If you need to mount a file system, you can use the mount command with the following syntax −
mount -t file_system_type device_to_mount directory_to_mount_to
For example, if you want to mount a CD-ROM to the directory /mnt/cdrom, you can type −
$ mount -t iso9660 /dev/cdrom /mnt/cdrom
This assumes that your CD-ROM device is called /dev/cdrom and that you want to mount it to /mnt/cdrom. Refer to the mount man page for more specific information or type mount -h at the command line for help information.
After mounting, you can use the cd command to navigate the newly available file system through the mount point you just made.
To unmount (remove) the file system from your system, use the umount command by identifying the mount point or device.
For example, to unmount cdrom, use the following command −
$ umount /dev/cdrom
The mount command enables you to access your file systems, but on most modern Unix systems, the automount function makes this process invisible to the user and requires no intervention.
The user and group quotas provide the mechanisms by which the amount of space used by a single user or all users within a specific group can be limited to a value defined by the administrator.
Quotas operate around two limits that allow the user to take some action if the amount of space or number of disk blocks start to exceed the administrator defined limits −
There are a number of commands to administer quotas −