Full Disks

In this example, we report when file systems are full.

The DiskCap script might send an alert message like the following:

                                PIKT ALERT
                         Wed Oct  3 04:30:06 2002
                                 athens4

EMERGENCY:
    DiskCap
        Report emergency full disk situations

        Filesystem /ckp on /dev/md/dsk/d10 is 100% full, 0 Kb left

        17370930        /ckp/ingres
        8               /ckp/lost+found

The DiskCap script makes reference to the DiskCaps.obj file.  The script follows.

DiskCap        // report, possibly take action, and possibly page if
               // capacity threshold exceeded (typically 100%--i.e.,
               // the file system is full)

        init
                status =piktstatus
                level =piktlevel
                task "Report emergency full disk situations"
                =dflinput
                =dffilter
                =dfdata
                keys $fsname

        begin
#ifdef page
		set $pagemsg = "$hostname() $mount is full"
#endifdef
                =readvals(=objdir/DiskCaps.obj, diskcapval, ":", 6)

        rule    // every $mount has its own #hr value
                set #hr = #hour()

        rule
                // the 1st val (2nd field) in DiskCaps.obj is the emergency field
                if $diskcapval["$mount 1"] ne $err()
                        set #caplim = #val($diskcapval["$mount 1"])
                        set $execcmd = $diskcapval["$mount 6"]
                else
                        set #caplim = #val($diskcapval["DEFAULT 1"])
                        set $execcmd = $diskcapval["DEFAULT 6"]
                endif

#ifdef debug
        rule
                output "$mount $text(#hr) $text(#cap*100)%
                        $text(#caplim*100)% $execcmd"
#endifdef

        rule    // report, possibly take action, and possibly page if
                // capacity threshold exceeded
                if    #cap >= #caplim
                   && =increased(cap, #caplim, 0%)
                        // report
                        output mail "Filesystem $mount on $fsname is
                                     $text(100*#cap,0)% full,
                                     $text(#avail) Kb left"
                        =dutop(10, $mount)
                        // possibly take action
                        if $execcmd ne ""
                                =exec $execcmd
                        endif
                        // possibly page
#ifdef page
#  if missioncritical
                                =hourly(=page($pagemsg, =pagesysadmins, =allhours(#now())), )
#    if db
                                =hourly(=page($pagemsg, =pagedbadmins, =allhours(#now())), )
#    endif
#  else
                                =every_four_hours(=page($pagemsg, =pagesysadmins,
                                                        ! =offhours(#now())), )
#  endif
#endifdef
                endif

Here is an alternative way to check for full disks using the script macro technique.

This is just one program example.  You could add rules, or write new scripts, for example to:  report hardware failures, report network cross-mounted disks going off-line, report problems with the RAID setup, clear /tmp files, log I/O stats, etc.

For more examples, see Samples.