CleanDisk^(tm)

This chapter explains how to shutdown CleanDisk.

5.1 Shutdown Instructions

In order to shut down CleanDisk, you should log into the SYSTEM account and run the @TTI _CD:CDSHUTDOWN procedure.

Example:

 
      USERNAME: SYSTEM 
      PASSWORD: (the system password) 
 
      $ @TTI_CD:CDSHUTDOWN 
        CD - CleanDisk (2.0) - CleanDisk Shutdown Procedure 
        Copyright (c) 1995 Touch Technologies, Inc. 
 
        CleanDisk server shutdown completed 
 
      $ LOGOUT 
 

All CleanDisk operations will be shutdown.

CD can be loaded into any directory on any disk ...e.g., $1$WORK:[CD]

The following is an example of the installation of CleanDisk on a OpenVMS computer system. Example A-1 Installing CleanDisk

    
        APPLICATIONS SYSTEM OpenVMS Version 6.1 
 
   Username:  SYSTEM 
   Password:  (the system password) 
 
   $ CREATE/DIRECTORY SYS$SYSDEVICE:[TTI_CD] 
   $ SET DEFAULT SYS$SYSDEVICE:[TTI_CD] 
   $ DIRECTORY 
      No files found. 
   $ ALLOCATE MSA0: 
    _MSA0: allocated 
   $ MOUNT MSA0:/FOREIGN 
   Volume is write locked 
   CD mounted on _MSA0: 
   $ BACKUP/LOG MSA0:*.*  *.*/NEW_VERSION 
           . 
           . 
   $ DISMOUNT MSA0: 
   $ DEALLOCATE MSA0: 

 
   $ 
   $ @CDSTARTUP 
   CD CleanDisk (2.0) - CDstartup Procedure 
   Copyright (c) 1995 Touch Technologies, Inc. 
   building CD_CONTROL_SHR_V62.EXE...           <-- Note: 
   building CD_SERVER_V62.EXE...                <--   These messages appear 
   building CD_CONTROL_V62.EXE...               <--   only the first time 
   building CDDDRIVER_V62.EXE...                <--   CleanDisk is installed 
   %RUN-S-PROC_ID, identification of created process is 30E001AA 
   CD startup completed 
                             . 
   $ log 
     SYSTEM       logged out at 01-MAY-1995 09:50:59.95 
 

The CleanDisk distribution directory contains less than 400 blocks of disk space.

CleanDisk runs as a detached process. CleanDisk also includes a pseudo device driver. This driver uses less than 5000 bytes of NPAGEDYN. In addition, about 50,000 bytes of NPAGEDYN are used for parameter and statistics buffers.

Because CleanDisk can dynamically control the window-size that a given file uses, we recommend a BYTLM of at least 25000.

CleanDisk uses the system logical TTI_CD to store the location of the CleanDisk package. This logical is created by the CDSTARTUP.COM command file.

The following logicals are used internally by CleanDisk:

Table B-1 CleanDisk Defined Logicals

CD_PID	PID of the CleanDisk detached process
CD_STATUS	Status of the last CleanDisk startup

Here are some often asked questions and answers.

C.1 If I have CleanDisk, can I still use my online disk defragmenter -- such as DISKEEPER?

Yes, CleanDisk works well as a companion product for any disk defragmentation software. Disk defragmenters constantly defragment files that are not being accessed. CleanDisk constantly does its best to keep open files from becoming excessively fragmented. Disk defragmenters create consolidated free space on the disk. Once files are deleted, by default, OpenVMS does not use the free space, but instead uses random file fragments found in the XQP extent cache. CleanDisk causes OpenVMS to use the consolidated free space as much as it can. The net result is reduced disk and file fragmentation and fewer disk I/Os.

CleanDisk not only causes your system to better use the contiguous space made available by a defragmenter, but also allows the defragmenter to do less work.

C.2 The CDSERVER process logs thousands of I/Os in the course of a day. What is it doing?

Every five seconds, CDSERVER asks the CLNdriver, a pseudo-device driver, to look for newly-created processes and enable CleanDisk on their behalf. This request is made via an "I/O request" to the CLNdriver. Although OpenVMS logs this as an "I/O operation" there is no data actually being read from or written to any external devices. (This is somewhat similar to a write to the null device.)

C.3 The CDCONTROL SHOW/ALL display shows that some processes do not have CleanDisk enabled. Why not?

There are several reasons:

1. Very recently created processes (within the last five seconds) may not have been seen yet by the auto-enable mechanism.
2. CleanDisk is not enabled for OpenVMS's SWAPPER process.
3. The auto-enable mechanism does not enable CleanDisk for processes which are outswapped or which are in any of several wait states (such as SUSPEND, MWAIT, etc.). Such processes will not be doing any disk I/O while they are in such states, so enabling CleanDisk for them will have no benefit. CleanDisk will be enabled for these processes once they leave these "long-term idle" states.

C.4 I have many existing files that get extended daily. How will CleanDisk keep these files from becomin g badly fragmented?

When the file is extended, if there is free space adjoining the last file extent, CleanDisk will concatenate this free space to the last extent. This causes the last extent to be larger...and avoids further file fragmentation. If there is not enough adjoining free space, CleanDisk will cause a contiguous-best-try extent to be created. The result is a significant reduction in daily file fragmentation!

C.5 I have other software products that intercept file opens. Will CleanDisk interfere with the operation of these products?

No, the CleanDisk intercept is probably at a level below where these types of products intercept file opens. CleanDisk intercepts at the XQP level. Even if other software products intercept at this level, CleanDisk will not interfere because CleanDisk specifically checks for other software products intercepting at the XQP level.

Index