Browse Prior Art Database

Disk Space Monitoring Program

IP.com Disclosure Number: IPCOM000121060D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 4 page(s) / 134K

Publishing Venue

IBM

Related People

Mock, WE: AUTHOR

Abstract

Disclosed is a program that monitors free disk space of computers running AIX* version 3.1. If necessary it increases the amount of free space to accommodate system load.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 45% of the total text.

Disk Space Monitoring Program

      Disclosed is a program that monitors free disk space of
computers running AIX* version 3.1.  If necessary it increases the
amount of free space to accommodate system load.

      AIX version 3.1 allows the allocated blocks of a logical volume
to be increased in real-time, even while other processes are
accessing the volume.  However, AIX v3.1 does not offer an automatic
way of increasing almost full volumes.  The disk space monitoring
(dsmon) program fills this gap.

      The dsmon program monitors the "percentage used" of each
specified volume.  If it goes beyond a set limit (80% is the
default), the number of allocated blocks is increased until the
percentage used is below a set limit (70% is the default).  This slow
growth rate closely simulates typical use of the system over time,
thus guaranteeing that blocks are allocated only as needed.  (You can
increase a volume size, but not decrease it.)  This conservative
approach keeps the dsmon program from allocating large blocks that
are never used.

      The dsmon program samples each volume's percentage used every
30 seconds.  This interval provides ample time to detect a critical
volume and correct the problem before the volume becomes 100% used.
The dsmon program outputs status messages at 15-minute intervals and
when a change in volume size is necessary.

      Because the system monitored by the dsmon program can run out
of physical disk space, the dsmon program includes a warning message
system.  If the program is unable to adequately increase disk space,
it displays a warning message on a specified tty of a specified host.
The defaults are the current tty and local host.  This gives the user
testing in a distributed, multi-machine environment the flexibility
to send warning messages to a central location. The machine that
sends a warning message requires immediate attention.  Otherwise, the
volumes will become full in a short amount of time.

      The dsmon program works best with operating systems that offer
a way to allocate more blocks to volumes (i.e., AIX v3.1).  But it
can also be useful to strictly monitor volumes of other systems.

      The dsmon program also monitors systems that do not offer a
real- time disk space allocation mechanism.  This feature allows the
tester time to clear space manually on the volume before the volume
reaches 100% capacity.  When the program detects a mostly full volume
(95% is the default), a warning message is sent to a central host to
alert the user running the tests.  The user then has the opportunity
to remove unneeded files from the volume using the rm command.
USAGE
usage:    dsmon.sh [-h host] [-o tty] [-t hours] <machine>
[-h host]   Name of the host monitoring <local host>
[-o tty]    Device to write to on <-h host> for warn
ings
[-t hours]  Hours to monitor <local host>. Default is forever.
                <machine>   Machine type...