Network-Accessible Storage Under Red Hat Enterprise Linux - Red Hat ENTERPRISE LINUX 3 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual

98
5.9.3.2.2. Viewing
/proc/mounts
The
/proc/mounts
the "file" does not exist on any disk drive in your Red Hat Enterprise Linux system.
mounts
In fact, it is not even a file; instead it is a representation of system status made available (by the Linux
kernel) in file form.
Using the command
rootfs / rootfs rw 0 0
/dev/root / ext3 rw 0 0
/proc /proc proc rw 0 0
usbdevfs /proc/bus/usb usbdevfs rw 0 0
/dev/sda1 /boot ext3 rw 0 0
none /dev/pts devpts rw 0 0
/dev/sda4 /home ext3 rw 0 0
none /dev/shm tmpfs rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
As we can see from the above example, the format of
. There are a number of file systems mounted that have nothing to do with disk drives.
/etc/mtab
Among these are the
), pseudo-ttys, and shared memory.
/proc/
While the format is admittedly not very user-friendly, looking at
be 100% sure of seeing what is mounted on your Red Hat Enterprise Linux system, as the kernel is
providing this information. Other methods can, under rare circumstances, be inaccurate.
However, most of the time you will likely use a command with more easily-read (and useful) output.
The next section describes that command.
5.9.3.2.3. Issuing the
While using
/etc/mtab
it does little beyond that. Most of the time you are more interested in one particular aspect of the file
systems that are currently mounted — the amount of free space on them.
For this, we can use the
Filesystem
/dev/sda3
/dev/sda1
/dev/sda4
none
Several differences from
An easy-to-read heading is displayed
•
With the exception of the shared memory file system, only disk-based file systems are shown
•
Total size, used space, free space, and percentage in use figures are displayed
•
That last point is probably the most important because every system administrator eventually has to
deal with a system that has run out of free disk space. With
lies.
file is part of the proc virtual file system. As with the other files under
cat /proc/mounts
file system itself (along with two other file systems mounted under
/proc/
Command
df
or
/proc/mounts
command. Here is some sample output from
df
1k-blocks
8428196 4280980
124427
8428196 4094232
644600
and
/etc/mtab
, we can view the status of all mounted file systems:
/proc/mounts
lets you know what file systems are currently mounted,
Used Available Use% Mounted on
3719084
18815 99188
3905832
0 644600
are immediately obvious:
/proc/mount
it is very easy to see where the problem
df
Chapter 5. Managing Storage
is very similar to that of
is the best way to
/proc/mounts
:
df
54% /
16% /boot
52% /home
0% /dev/shm
,
/proc/