The percentage free space threshold, along with email addresses and domain names (aka workgroup names) are configured in a file named ocsdiff_conf.php. I run this (and other reports which I may post later) from a new subdirectory named reports that I created under /var/www/html/ocsreports. Be sure to set the same ownership and permissions on files in this directory as the other files under ocsreports. Here is what the file looks like:

> ocsdiff_conf.php

<?php
# ocsdiff configuration file
#
# Database host
$dbhost = "localhost";
$dbname = "ocsweb";
$dbuser = "ocs";
$dbpass = "XXX";
$adminemail = "admin@yourdomain.tld";
$diskthreshold = 5; # percentage free space threshold
$domains = array(
		0 => array(
			'name' => 'XXXXX',
			'email' => "fred@yourdomain.tld,barney@yourdomain.tld"),
		1 => array(
			'name' => 'YYYYY',
			'email' => "wilma@yourdomain.tld"),
		2 => array(
			'name' => 'ZZZZZ',
			'email' => "betty@yourdomain.tld"));
$diskdomains = array(
		0 => array(
			'name' => 'XXXXX',
			'email' => "fred@yourdomain.tld,barney@yourdomain.tld"),
		1 => array(
			'name' => 'YYYYY',
			'email' => "wilma@yourdomain.tld"),
		2 => array(
			'name' => 'ZZZZZ',
			'email' => "betty@yourdomain.tld"));
?>

The file is named like this because the first report I wrote was to generate reports on hardware changes (RAM and disk in particular). I know reports like this can be implemented using GLPI integration – but we already have a helpdesk/ticketing system and I just can’t justify the effort to setup GLPI when writing one’s own reports is just not that hard.

The report itself is contained in the code below, I named the file diskreport.php and I scheduled it to run everyday using cron. I run my cron jobs for OCS-NG reports under the apache account.

> diskreport.php

<?php
# This program will generate a daily report of disks with free space
# below a threshold set in the configuration file 
# Written by Mike Seigafuse July 2007
#
# Get the configuration file
require_once("ocsdiff_conf.php");
# Initialize headers so that email will be readable as Excel attachment
$today = date("Y-m-d G:i:s");
$headers = "From: ITInventory@yourdomain.tld\\r\\n";
$headers .= "Reply-To: ITInventory@yourdomain.tld\\r\\n";
$headers .= "MIME-Version: 1.0\\r\\n";
$headers .= "Content-type: text/html; charset=iso-8859-1\\r\\n";
$headers .= "Content-type: application/vnd.ms-excel\\r\\n";
$headers .= "Content-disposition: attachment; filename=$today.csv\\r\\n";
# Connect to database
$link = mysql_connect("$dbhost", "$dbuser", "$dbpass")
    or die("Could not connect : " . mysql_error());
mysql_select_db("$dbname") or die("Could not select database");
# Now loop through the defined disk domains and prepare report 
for($i = 0; $i < sizeof($diskdomains); $i++) {
	$entry = $diskdomains[$i];
	$name = $entry['name'];
	$email = $entry['email'];
	$subject = "Daily Disk Utilization Report for domain $name";
	$msg = "Computer Name,Drive Letter,Type,Filesystem,Total,Free,Free %\\n";
	# Now we have the domain name and contact, next get a current list of
	# deviceIDs from this domain
	$query = "select id, name, userid from hardware where workgroup='$name' and osname like '%server%'";
	$deviceresults = mysql_query($query)  or die("Query failed : " . mysql_error());
	while ($line = mysql_fetch_array($deviceresults, MYSQL_ASSOC)) {
		$deviceid = $line['id'];
		$computername = rtrim($line['name']);
		# Disk checking section
		$query = "select letter, type, filesystem, total, free
			from drives
			where hardware_id='$deviceid' and
			type = 'Hard Drive'";
		$diskresults = mysql_query($query)  or die("Query failed : " . mysql_error());
		# All information is now collected, now generate output 
		while ($diskline = mysql_fetch_array($diskresults, MYSQL_ASSOC)) {
			$driveletter = $diskline['letter'];
			$drivetype = $diskline['type'];
			$drivefs = $diskline['filesystem'];
			$drivetotal = $diskline['total'];
			$drivefree = $diskline['free'];
			$freeperc = (($drivefree/$drivetotal) * 100);
			if ($freeperc < $diskthreshold) {
				$msg .= "$computername,$driveletter,$drivetype,$drivefs,$drivetotal,$drivefree,$freeperc\\n";
				}
			} # end of disk loop
		} # end of devices in a domain loop
	# send out the email for this domain
	if ($msg == "") $msg = "No disk space issues found\\n";
	mail("$email", $subject, $msg, $headers);
	} # end of domain loop
# Almost done, just need to free up result memory
mysql_free_result($deviceresults);
mysql_free_result($diskresults);
# The End :)
?>

Be sure to change the From and Reply To addresses in at the top of the file to suit yourself. If I have time I will move this to the configuration file.

My version of OCS-NG displays 4020 on the screen, I believe this equates to V1.0 (I know 1.01 is released, but just haven’t had the time to upgrade yet). I am running on RHEL 4.

Use the link below to download a zip file of both of these files. If you have any comments or questions post a comment on this post and I will reply.

After the restore the system administrator attempted to reboot, and was informed that the system could not find the boot file. Now what? No worries, simply do the following:

• Insert the install CD and boot from it
• Hit F5, and then enter Linux rescue
• Select OK to search for Linux installs
• Select continue to mount the install disk found

Once you get to the command prompt do the following:

• cd /mnt/sysimage/boot/grub
• TERM=VT100;export TERM
• vi grub.conf

You should see a file that looks like this:

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You do not have a /boot partition. This means that
# all kernel and initrd paths are relative to /, eg.
# root (hd0,1)
# kernel /boot/vmlinuz-version ro root=/dev/sda2
# initrd /boot/initrd-version.img
#boot=/dev/sda
default=0
timeout=10
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
title Red Hat Enterprise Linux ES (2.4.21-40.EL)
root (hd0,0)
kernel /boot/vmlinuz-2.4.21-40.EL ro root=LABEL=/
initrd /boot/initrd-2.4.21-40.EL.img
title Red Hat Enterprise Linux ES (2.4.21-20.EL)
root (hd0,0)
kernel /boot/vmlinuz-2.4.21-20.EL ro root=LABEL=/
initrd /boot/initrd-2.4.21-20.EL.img

The bolded entries above are the ones of interest. hd0 is obviously the first hard drive, and the 0 after the comma is the partition on that disk. In our case the original system had the boot partition located on partition 1 but after the rebuild I changed it as indicated here to what you see 0. If you aren’t sure which partition is which you should be able to enter command line mode in grub after your boot fails by entering “c”. Then by entering “geometry (hd0)” which should display something like this:

grub> geometry (hd0)
drive 0×80: C/H/S = 6637/255/63, The number of sectors = 106633728, /dev/sda
Partition num: 0, Filesystem type is ext2fs, partition type 0×83
Partition num: 1, Filesystem type is ext2fs, partition type 0×83
Partition num: 2, Filesystem type is ext2fs, partition type 0×83
Partition num: 4, Filesystem type is ext2fs, partition type 0×83
Partition num: 5, Filesystem type is ext2fs, partition type 0×83
Partition num: 6, Filesystem type unknown, partition type 0×82
Partition num: 7, Filesystem type is ext2fs, partition type 0×83 grub>

Good information, but which one is /boot? Try entering the below and you will get your answer:

grub> find /boot/grub/grub.conf
(hd0,0)

Partition 0 is /boot on this system – your mileage may vary