Based on the check_win_snmp_disk.pl script posted here by jakubowski Benjamin, this enhanced version: * prints usage information if incorrect parameters are given * handles exceptions (more) gracefully * automatically scales output to TiB, GiB, MiB or KiB I have tested this updated script against Windows 2003 server (including R2) only, but it should work with most windows hosts.

#!/usr/bin/perl
# Enhanced by: Dan Capper
# Date: 13/11/2007
# Based on original script:
# Author : jakubowski Benjamin
# Date : 19/12/2005
# check_win_snmp_disk.pl SERVEUR COMMUNITY

# ------------ "Nearest" routines (round to a multiple of any number)
# Copied from Math::Round on cpan.org
# Math::Round was written by Geoffrey Rommel Cette adresse email est protégée contre les robots des spammeurs, vous devez activer Javascript pour la voir. in October 2000.

sub nearest {
my ($targ, @inputs) = @_;
my @res = ();
my $x;

$targ = abs($targ) if $targ < 0;
foreach $x (@inputs) {
if ($x >= 0) {
push @res, $targ * int(($x + $half * $targ) / $targ);
} else {
push @res, $targ * POSIX::ceil(($x - $half * $targ) / $targ);
}
}
return (wantarray) ? @res : $res[0];
}

$STATE_OK = 0;
$STATE_WARNING = 1;
$STATE_CRITICAL = 2;
$STATE_ERROR = 255;

# IEC Multipliers
$TEBI = 1099511627776;
$GIBI = 1073741824;
$MEBI = 1048576;
$KIBI = 1024;

if ($#ARGV + 1 < 5) {
print "Enhanced check_win_snmp_disk.pl by Dan Capper based on original script by jakubowski Benjamin\n";
print "Reports disk usage of Windows systems via snmp to nagios\n";
print "\n";
print "usage:\n";
print "check_win_snmp_disk.pl [address] [community-name] [logical disk] [warn-level] [critical-level]\n";
print "Where:\n";
print "[address] = ip address or name of server to check\n";
print "[community-name] = SNMP community name with at least READ ONLY rights to server\n";
print "[logical disk] = Logical disk number of disk to check - on windows systems, 0 = A:, 1 = C:, 2 = D:, etc\n";
print "[warn-level] = Percentage full before return warning level to nagios\n";
print "[critical-level] = Percentage full before return critical level to nagios\n";
print "For example the command:\n";
print "./check_win_snmp_disk.pl 10.0.0.10 public 2 80 90\n";
print "Will check disk 'C:' on the server at '10.0.0.10' using snmp community name 'public'. Warn at 80% full, Critical at 90% full\n";
exit $STATE_ERROR;
}

if (@ARGV[0] =~ m/((\d{1,3}\.){3}\d{1,3})|(\w+)/) {
$SERVER = @ARGV[0];
} else {
print "ERROR: address argument not in correct format\n";
print "Execute with no parameters to see usage information\n";
exit $STATE_ERROR;
}

if (@ARGV[1] =~ m/\w+/) {
$COMMUNITYNAME=@ARGV[1];
} else {
print "ERROR: community-name argument not in correct format\n";
print "Execute with no parameters to see usage information\n";
exit $STATE_ERROR;
}

if (@ARGV[2] =~ m/\d{1,2}/) {
$LDISK=@ARGV[2];
} else {
print "ERROR: logical disk argument not in correct format\n";
print "Execute with no parameters to see usage information\n";
exit $STATE_ERROR;
}

if (@ARGV[4] =~ m/\d{1,3}/ and @ARGV[4] <= 100) {
$CRITICAL=@ARGV[4];
} else {
print "ERROR: critical argument not in correct format\n";
print "critical level must no more than 100\n";
print "Execute with no parameters to see usage information\n";
exit $STATE_ERROR;
}

if (@ARGV[3] =~ m/\d{1,3}/ and @ARGV[3] <= 100 and @ARGV[3] <= $CRITICAL) {
$WARN=@ARGV[3];
} else {
print "ERROR: warning-level argument not in correct format\n";
print "warning-level must no more than 100 and less than critical level\n";
print "Execute with no parameters to see usage information\n";
exit $STATE_ERROR;
}

# Used Space
$RAWUSED=`snmpget -v 1 $SERVER -c $COMMUNITYNAME .iso.org.dod.internet.mgmt.mib-2.host.hrStorage.hrStorageTable.hrStorageEntry.hrStorageUsed.$LDISK -t 5| awk '{ print \$4 }'`;
$RAWUSED =~ s/\n//g;
if ($RAWUSED !~ m/\d+/) {
print "ERROR : Unexpected result from snmpget\n";
exit $STATE_ERROR;
}

# Size of disk
$RAWSIZE=`/usr/bin/snmpget -v 1 $SERVER -c $COMMUNITYNAME .iso.org.dod.internet.mgmt.mib-2.host.hrStorage.hrStorageTable.hrStorageEntry.hrStorageSize.$LDISK -t 5| awk '{ print \$4 }'`;
$RAWSIZE =~ s/\n//g;
if ($RAWSIZE !~ m/\d+/) {
print "ERROR : Unexpected result from snmpget\n";
exit $STATE_ERROR;
}

# GET BYTE VALUE FOR DISK SYSTEM (512;1024;2048;4096)
$VALUE=`/usr/bin/snmpget -v 1 $SERVER -c $COMMUNITYNAME .iso.org.dod.internet.mgmt.mib-2.host.hrStorage.hrStorageTable.hrStorageEntry.hrStorageAllocationUnits.$LDISK -t 5 | awk '{ print \$4 }'`;

$VALUE =~ s/\n//g;
if ($VALUE !~ m/\d+/) {
print "ERROR : Unexpected result from snmpget\n";
exit $STATE_ERROR;
}

# Calculate percentage used

SWITCH: {
if ($RAWSIZE > 0) { $PERCENTUSED = nearest(.1, $RAWUSED/$RAWSIZE * 100); last SWITCH; };
$PERCENTUSED = 0;
}

# Calculate human-readable total space

SWITCH: {
if ($RAWSIZE * $VALUE >= $TEBI) { $TOTAL = nearest(.1, $RAWSIZE * $VALUE/($TEBI)); $TOTALUNITS = "TiB"; last SWITCH; };
if ($RAWSIZE * $VALUE >= $GIBI) { $TOTAL = nearest(.1, $RAWSIZE * $VALUE/($GIBI)); $TOTALUNITS = "GiB"; last SWITCH; };
if ($RAWSIZE * $VALUE >= $MEBI) { $TOTAL = nearest(.1, $RAWSIZE * $VALUE/($MEBI)); $TOTALUNITS = "MiB"; last SWITCH; };
if ($RAWSIZE * $VALUE >= $KIBI) { $TOTAL = nearest(.1, $RAWSIZE * $VALUE/($KIBI)); $TOTALUNITS = "KiB"; last SWITCH; };
if ($RAWSIZE > 0) { $TOTAL = nearest(.1, $RAWTOTAL * $VALUE); $TOTALUNITS = "B"; last SWITCH; };
$TOTAL = 0;
}

# Calculate human-readable used space

SWITCH: {
if ($RAWUSED * $VALUE >= $TEBI) { $USED = nearest(.1, $RAWUSED * $VALUE/($TEBI)); $USEDUNITS = "TiB"; last SWITCH; };
if ($RAWUSED * $VALUE >= $GIBI) { $USED = nearest(.1, $RAWUSED * $VALUE/($GIBI)); $USEDUNITS = "GiB"; last SWITCH; };
if ($RAWUSED * $VALUE >= $MEBI) { $USED = nearest(.1, $RAWUSED * $VALUE/($MEBI)); $USEDUNITS = "MiB"; last SWITCH; };
if ($RAWUSED * $VALUE >= $KIBI) { $USED = nearest(.1, $RAWUSED * $VALUE/($KIBI)); $USEDUNITS = "KiB"; last SWITCH; };
if ($RAWUSED * $VALUE > 0) { $USED = nearest(.1, $RAWUSED * $VALUE); $USEDUNITS = "B"; last SWITCH; };
$USED = 0;
}

# Calculate Free Space

$RAWFREE=$RAWSIZE-$RAWUSED;

# Calculate human-readable free space

SWITCH: {
if ($RAWFREE * $VALUE >= $TEBI) { $FREE = nearest(.1, $RAWFREE * $VALUE/($TEBI)); $FREEUNITS = "TiB"; last SWITCH; };
if ($RAWFREE * $VALUE >= $GIBI) { $FREE = nearest(.1, $RAWFREE * $VALUE/($GIBI)); $FREEUNITS = "GiB"; last SWITCH; };
if ($RAWFREE * $VALUE >= $MEBI) { $FREE = nearest(.1, $RAWFREE * $VALUE/($MEBI)); $FREEUNITS = "MiB"; last SWITCH; };
if ($RAWFREE * $VALUE >= $KIBI) { $FREE = nearest(.1, $RAWFREE * $VALUE/($KIBI)); $FREEUNITS = "KiB"; last SWITCH; };
if ($RAWFREE > 0) { $FREE = nearest(.1, $RAWFREE * $VALUE); $FREEUNITS = "B"; last SWITCH; };
$FREE = 0;
}

if ( $PERCENTUSED < $WARN ) {
print "OK : Percent Used : $PERCENTUSED%, Total : $TOTAL $TOTALUNITS, Used : $USED $USEDUNITS, Free : $FREE $FREEUNITS\n";
exit $STATE_OK;
}

if ( $PERCENTUSED < $CRITICAL ) {
print "WARNING : Percent Used : $PERCENTUSED%, Total : $TOTAL $TOTALUNITS, Used : $USED $USEDUNITS, Free : $FREE $FREEUNITS\n";
exit $STATE_WARNING;
}

if ( $PERCENTUSED >= $CRITICAL ) {
print "CRITICAL : Percent Used : $PERCENTUSED%, Total : $TOTAL $TOTALUNITS, Used : $USED $USEDUNITS, Free : $FREE $FREEUNITS\n";
exit $STATE_CRITICAL;
}

print "ERROR : Unexpected Results : Percent Used : $PERCENTUSED%, Total : $TOTAL $TOTALUNITS, Used : $USED $USEDUNITS, Free : $FREE $FREEUNITS\n";
exit $STATE_ERROR;