Software Product Description
GCE Deletion Protection System (DPS)
Description: The GCE Deletion Protection System is designed to
provide protection against accidental deletion of file types
chosen by the site, and to allow files to be routed by the
system to backup media before they are finally removed from the
system. This is accomplished by an add-in to the VMS file system
so that security holes are not introduced by the system's
action.
The user interface is an UNDELETE command which permits one or
more files to be restored to their original locations provided
it is issued within the site-chosen time window after the undesired
deletion took place. In addition, an EXPUNGE command is provided
which allows files to be deleted at once, irretrievably, where
space for such is required. Provision for automatic safe-storing
of files prior to final deletion is present also in DPS.
DPS is implemented as a VMS file system add-in which functions
by intercepting the DELETE operation and allowing the file to be
deleted to be copied or renamed to a "wastebasket" holding area
pending final action, and to be disposed of by a disposal agent.
The supplied agent will allow a site script to save the files if
this is desired, and then finally deletes any files which have
been deleted more than some number N seconds ago. If the
UNDELETE command is given, the file(s) undeleted are replaced in
their original sites. The supplied system can also be configured
to rename files to a wastebasket area or to copy them directly,
for undeletion by systems people only. (These options are faster
than the site command file option.)
DPS can be configured to omit certain file types from deletion
protection (for example, *.LIS* or *.MAP* could be omitted), to
include only certain files in the protected sets, or both. This
can reduce the overhead of saving files which are likely to be
easily recreated, or tailor the system for such actions as
saving all mail files (by selecting *.MAI for inclusion).
In addition, DPS monitors free space on disks, and when a file
create or extend would cause space exhaustion, DPS runs a site
script. By setting this script to perform final deletions, DPS
can be run in a purely automatic mode in which deleted files are
saved as long as possible, but never less than some minimum
period (e.g., 5 or 10 minutes).
DPS files can be stored in any location accessible to VMS. If
they are renamed, they must reside on the same disk they came
from. Otherwise they can be stored in any desired place.
DPS is installed and configured using a screen oriented
configuration utility to set it up, and basically runs
unattended once installed.
Supported Hardware and Software:
DPS runs on any VMS Vax or Alpha/AXP platform. On Vax it
supports VMS 5.5 or later. On AXP it supports VMS 6.1 or later.
Internally, DPS uses only published and supported internal VMS
interfaces, and thus is independent of which file system is in
use. However, its use with third party file systems such as NFS
client systems is untested and should be tested before a site
commits to using it heavily.
DPS is available for 45 day trial use licenses or can be
licensed permanently. DPS is required on every node of a cluster
using it, or its benefits will not be available on nodes not
having the software running. Apart from this, there are no
problems with having DPS available on only part of a VMS
cluster.
Deletion Protection System
General Cybernetic Engineering
Glenn C. Everhart
18 Colburn Lane
Hollis, NH 03049
603 465 9517 (Fax: 603 465 9518)
Everhart@GCE.Com
(Everhart@gce.mv.com)