Installation guide

Chapter 20. Gathering System Information 175
the last line in the list. If you do not want to see all the subdirectories, use the command
du -hs to see only the grand total for the directory in human-readable format. Use the du
--help command to see more options.
20.3.1. Monitoring Filesystems
Red Hat Linux provides a utility called diskcheck that monitors the amount of free disk
space on the system. Based on the configuration file, it will send email to the system admin-
istrator when one or more disk drives reach a specified capacity.
This utility is run as an hourly cron
1
task.
The following variables can be defined in /etc/diskcheck.conf:
• defaultCutoff — When disk drives reach this percent capacity, it will be reported. For
example, if defaultCutoff = 90, an email will be sent when the monitored disk drives
reach 90% capacity.
• cutoff[/dev/partition] — Override the defaultCutoff for the partition. For example,
if cutoff[’/dev/hda3’] = 50 is specified, diskcheck will alert the system administrator
when the partition /dev/hda3 reaches 50% capacity.
• cutoff[/mountpoint] — Override the defaultCutoff for the mount point. For exam-
ple, if cutoff[’/home’] = 50 is specified, diskcheck will alert the system administrator
when the mount point /home reaches 50% capacity.
• exclude — Specify one or more partitions for diskcheck to ignore. For example, if ex-
clude = "/dev/sda2 /dev/sda4" is specified, diskcheck will not alert the system ad-
ministrator if /dev/sda2 or /dev/sda4 reaches the specified cutoff percentage.
• ignore — Specify one or more filesystem types to ignore in the format -x filesystem-
type. For example, if ignore = "-x nfs -x iso9660" is specified, the system adminis-
trator will not be alerted about nfs or iso9660 filesystems reaching capacity.
• mailTo — Email address of the system administrator to alert when partitions and mount
points reach the specified capacity. For example, if mailTo = "[e-mail]"
is specified, [e-mail] will be emailed alerts.
• mailFrom — Specify the identity of the email sender. This is useful if the system adminis-
trator wants to filter the mail from diskcheck. For example, if mailFrom = "Disk Usage
Monitor" is specified, email will be sent to the system administrator with the sender Disk
Usage Monitor.
• mailProg — Specify the mail program to use to sent email alerts. For example, if mailProg
= "/usr/sbin/sendmail" is specified, Sendmail will be used as the mail program.
You do not have to restart a service if you change the configuration file because it is read
each time the cron task is run.
20.4. Hardware
If you are having trouble configuring your hardware or just want to know what hardware
is in your system, you can use the Hardware Browser application to display the hardware
that can be probed. To start the program, type hwbrowser at a shell prompt. As shown in
Figure 20-4, it displays your CD-ROM devices, floppy disks, hard drives and their partitions,
1. Refer to Chapter 22 for more information on cron.