Help w/Disk usage utility

[Tom Christiansen]

>From the keyboard of arthur at ccwf.cc.utexas.edu (Arthur Nghiem):
:	I want to write a script that will check the disk usage of a group
:of users periodically.  I want to be able to warn them when they first exceed
:a limit, wait a few days and then automatically compress their files or
:remove the newest files that put them over the limit.
:        I'm hoping that someone has already done this and will be happy
:to help out.  Please send mail to arthur at ccwf.ccutexas.edu.  Scripting in
:any shell and/or alernate solutions will be joyfully accepted.

You should be able to massage this into somethin useful.    It finds
full filesystems (you get to define how full is full, on a per-fs basis)
and mails only the top offenders about it.  Works quite well here.


For example, here's my $EXCEPT file:

    # this file used by dfbitch disk monitoring program to find
    # filesystems whose allowable freespace is different
    # from the default.

    # to reset minimum allowable free space, uncomment next line
    # MIN_FREE	90

    # file system	percentage allowed full

     /export/swap	105
     /export/swap2	105
     /usr		100
     /mnt		 99
     /tmp		 50

    # vwork and vmaster changed by K<bob> 9/11/90:

     /vwork		111
     /vmaster           111
     /bobm		150


The script follows.  It uses /usr/etc/quot, /bin/df,  /usr/lib/sendmail.
You can get get by without sendmail, but not the others.

See also the posting by Johan Vromans <jv at mh.nl> in the article
<1991Feb28.104805.24928 at pronto.mh.nl> to alt.sources and comp.lang.perl
entitled "dusage.pl (Was: Re: monitoring disk usage...)".  It came out
last Thursday.


--tom

#!/usr/bin/perl 
#
# dfbitch - check for "full" disks, mailing top users about the problem
# tom christiansen, 9-sep-90
#
# "full" is defined as having more than $MIN_FREE percent usesd,
# unless the file system is mentioned in the $EXCEPT file, which
# should consist of ordered pairs of filesystems and minfree values.

$MIN_FREE  = 97;	# unless in EXCEPT file, want this much free
$MIN_WHINE = 5; 	# don't whine at someone with less than this %

$EXCEPT    = '/usr/adm/etc/capacities';

chop($hostname = `hostname`);

&read_exceptions;

open(DF, "df -t 4.2|");
$_ = <DF>; 		# skip header
while ( <DF> ) {
    chop;
    ($disk, $kbytes, $used, $avail, $capacity, $mpnt) = split;
    $capacity =~ s/%//;
    if ( $capacity > (defined($Max{$mpnt}) ? $Max{$mpnt} : $MIN_FREE)) {
	&too_full($mpnt, $used, $capacity);
    } 
} 
close DF;
exit;

# ---------------------------------------------------------------------------

sub read_exceptions {
    local($fs, $min_free);
    # global $EXCEPT %Max

    if (-e $EXCEPT) {
	open EXCEPT || die "can't open $EXCEPT: $!";
	while ( <EXCEPT> ) {
	    next if /^\s*#/ || /^\s*$/;
	    chop;
	    ($fs, $min_free) = split(' ');
	    if ($fs =~ /^min_?free/i) {
		$MIN_FREE = $min_free;
	    } else {
		$Max{$fs} = $min_free;
	    } 
	} 
	close EXCEPT;
    } 
}

# ---------------------------------------------------------------------------

sub too_full {
    local($fs, $kused, $percen) = @_;
    local($_, $used, $user, $anon, @anon, @lines, @allusers, @abusers);

    open (QUOT, "/usr/etc/quot $fs|");
    $_ = <QUOT>;  # skip header

    while ( <QUOT> ) {
	push(@lines, $_);
	chop;
	($used, $user) = split(' ');
	if ($user =~ /^#/) {
	    push(@anon, $user);
	    $anon =+ $used;
	    next;
	} 
	push(@allusers, $user);
	push(@abusers, $user) 	unless $used/$kused < ($MIN_WHINE/100);
    } 
    close QUOT;
    die "couldn't run quot on $fs" if $? || $#allusers < 0;

    $rcpts = join(", ", ($#abusers < 0) ? @allusers : @abusers);

    if (0 && $anon) { # maybe someday
	print "Should remind root that $anon kbytes on $fs are used by ";
	print "defunct users ", join(', ', @anon), "\n";
    } 

    open (MAIL, "| /usr/lib/sendmail -oi -t");
    select(MAIL);

    print <<EOM;
From: the Disk Monitor Daemon ($0) <daemon>
To: $rcpts
Cc: root
Subject: $fs on $hostname is $percen% full

Each of you is taking up at least $MIN_WHINE% of the space on $hostname:$fs.
Please do what you can to reduce this.  You might consider simply removing
extraneous files, moving some files to other filesystems, compressing them, 
or backing them up on tape and then deleting them.

your friend, the daemon

PS: here are the exact totals in kilobytes for top users:

EOM

    print @lines[0..$#abusers];
    print "\n";
    close MAIL;
    select(STDOUT);
} 
--
"UNIX was not designed to stop you from doing stupid things, because
 that would also stop you from doing clever things." -- Doug Gwyn

 Tom Christiansen                tchrist at convex.com      convex!tchrist