Dynamic Load Balancer Plustm
Previous Contents Index

Chapter 2
Installation Set Up Procedures

Note
In order to install DLB Plus, it is ESSENTIAL to make the system parameter changes described in this chapter. FAILURE TO MAKE THE REQUIRED CHANGES WILL GREATLY REDUCE THE BENEFITS OF DLB Plus.

After making changes to STATIC SYSGEN parameters, the system must be rebooted for the changes to take effect.

2.1 Pages and Pagelets

On VAX systems, a PAGE is 512 bytes of memory. On Alpha systems, a PAGE can be any number of bytes. For example: 8192 bytes.

With OpenVMS V6.1, the new term or concept PAGELET was created. A PAGELET is 512 bytes of memory.

On a VAX, both a PAGE and a PAGELET are 512 bytes of memory. On Alpha systems, a PAGE might be 8192 bytes (it can vary) which is 16 PAGELETS (8192/512 = 16).

On the DLB Plus DISPLAY screen, the items: 


                Total Sys Memory       PAGES 
                Free List Size         PAGES 
                Modifed Lst Size       PAGES

are in PAGES and other memory related items are in PAGELETS.

On the DLB Plus STATUS screen, the items: 


                Total System Memory    PAGES 
                Free List Size         PAGES 
                Modifed List Size      PAGES 
                MPW_THRESH             PAGES 
                MPW_HILIMIT            PAGES 
                MPW_LOWAITLIMIT        PAGES

are in PAGES and other memory related items are in PAGELETS.

2.2 Required Sysgen Parameter Changes

The following static SYSGEN parameter settings are required. These settings allow DLB Plus to efficiently perform its dynamic tuning tasks. Use the OpenVMS SYSGEN facility or the OpenVMS AUTOGEN procedure to make these required SYSGEN changes.

2.2.1 SYSGEN Parameter Values

DLB Plus requires that you change two SYSGEN parameters. They are:

DLB Plus requires a greatly increased Modified Page List. DLB Plus uses the modified page list as a page filtering cache. Using this cache, DLB Plus causes OpenVMS to accurately determine which memory pages each process requires and which pages can be given back to the Free List. The SYSGEN parameter MPW_HILIMIT controls the size of the Modified Page List. In order to work efficiently, DLB Plus requires that MPW_HILIMIT be set to 15 percent of total memory or a maximum of 65535 pages.

MPW_WAITLIMIT must be set to the same value or higher than MPW_HILIMIT. If you forget to change MPW_WAITLIMIT, OpenVMS will correctly change it for you.

2.3 Changing Required SYSGEN Parameter Values

Table 2-1 SYSGEN Parameter Changes
Parameter New Value
MPW_HILIMIT 15% of total memory pages
MPW_WAITLIMIT equal to MPW_HILIMIT

For example, if you have 32MB of memory (65536 pages) on your system, the new SYSGEN values would be:

MPW_HILIMIT = 15% of 65536 or 9830 pages

MPW_WAITLIMIT = MPW_HILIMIT or 9830 pages

The SYSGEN parameter changes can be made either directly through the OpenVMS SYSGEN utility, or by adding the following lines to your SYS$SYSTEM:MODPARAMS.DAT file and running the Digital supplied SYS$UPDATE:AUTOGEN.COM procedure.

If you plan to use the Digital supplied SYS$UPDATE:AUTOGEN.COM procedure, you will first need to make two additions to SYS$SYSTEM:MODPARAMS.DAT.

After making these static SYSGEN parameter changes, you must reboot your system in order for the changes to take effect.

Example 2-1 Making Additions to SYS$SYSTEM:MODPARAMS.DAT for VAX 


$ edit sys$system:modparams.dat 
   . 
   .   ! go to the bottom of the file 
   .   ! add the following lines 
   . 
  MPW_HILIMIT        = (MEMSIZE*15)/100   ! change for DLB Plus 
  MPW_WAITLIMIT      = MPW_HILIMIT        ! change for DLB Plus 
   . 
   .   ! exit from the editor 
   .

Example 2-2 Making Additions to SYS$SYSTEM:MODPARAMS.DAT for Alpha 


$ edit sys$system:modparams.dat 
   . 
   .   ! go to the bottom of the file 
   .   ! add the following lines 
   . 
  MPW_HILIMIT        = (MEMSIZE_PAGES*15)/100      ! change for DLB Plus 
  MPW_WAITLIMIT      = MPW_HILIMIT                 ! change for DLB Plus 
   . 
   .   ! exit from the editor 
   .

Note
MEMSIZE and MEMSIZE_PAGES are AUTOGEN supplied symbols that contain the number of pages or pagelets of memory on your VAX or Alpha system.

2.4 PAGEFILE Requirements

As DLB Plus moves infrequently accessed memory pages out of process working sets, many of the pages end up being written by OpenVMS to pagefiles. If the pagefiles get full, system performance will degrade. Therefore, it is important that you have enough pagefile space.

The Digital supplied command SHOW MEMORY/PHYSICAL/FILES displays the total amount of memory and the current size of all swapfiles and pagefiles. 



$ SHOW MEMORY/PHYSICAL/FILES 
 
              System Memory Resources on 1-SEP-1995 15:37:08.62 
 
Physical Memory Usage (pages):     Total        Free      In Use    Modified 
  Main Memory (32.00Mb)            65536       33393       26315        5828 
 
Paging File Usage (pages):                      Free  Reservable       Total 
  DISK$FASTSYS:[SYS0.SYSEXE]SWAPFILE.SYS        6176        6176        7496 
  DISK$FASTSYS:[SYS0.SYSEXE]PAGEFILE.SYS       22736        8543       25000 
  FASTSTORAGE:[SYSFILES]PAGEFILE1.SYS;1       190542      135167      199992 
 
Of the physical pages in use, 12084 pages are permanently allocated to VMS.

2.4.1 PAGEFILE Sizing Guidelines

PAGEFILE sizes are normally sufficient if the combined total size of all pagefiles equals double the amount of total physical memory. In addition, during peak times you should have at least 33% of each pagefile free. Having sufficiently large pagefiles greatly enhances system performance.

In the example above, the system has 32MB of memory. This is 65536 memory pages. So, the combined sizes of all pagefiles should be at least 65536*2, or 131072 pages.

We have two pagefiles. One is 25000 pages, the other is 199992 pages, for a total of 224992 pagefile pages. So, we have enough pagefile space for DLB Plus to work efficiently.

2.4.2 Extending the Size of a Pagefile

If you need to extend the size of an existing PAGEFILE, use the Digital supplied SYSGEN utility. For example, to change the size of DISK$FASTSYS:[SYS0.SYSEXE]PAGEFILE.SYS from 25000 pages to 75000 pages, enter the following: 



$ RUN SYS$SYSTEM:SYSGEN 
SYSGEN> CREATE DISK$FASTSYS:[SYS0.SYSEXE]PAGEFILE.SYS/SIZE=75000 
DISK$FASTSYS:[SYS0.SYSEXE]PAGEFILE.SYS;1 extended 
SYSGEN> EXIT

Note
Although we are extending the PAGEFILE size, the command to both extend and create PAGEFILES is CREATE.

Chapter 3
Installing DLB Plus

Note
Read this manual COMPLETELY before installing DLB Plus on your VAX or Alpha.

DLB Plus can be installed on any VAX or Alpha computer running under:

The following items are included with this installation package:

3.1 License Registration

You should register and load the License PAK before you start the DLB PLUS installation.

To register a license under OpenVMS, first log in to the system manager's account, SYSTEM. You then have a choice of two ways to perform the registration:

  1. Invoke the SYS$UPDATE:VMSLICENSE.COM procedure. When it prompts you for information, respond with data from your License PAK.
  2. At the DCL prompt, enter the LICENSE REGISTER command with the appropriate qualifiers that correspond to License PAK information.

If you plan to use DLB Plus on more than one node in a cluster, you will need to perform a license load on the other nodes after you complete this installation.

3.2 Installation Instructions

To install DLB Plus on your VAX or Alpha computer, you need to work from a DEC VT100 or compatible terminal. Follow the steps listed below and type the commands shown. Because the VAX and Alpha systems are space conscious, be sure to type the commands EXACTLY as shown.

  1. Log onto the SYSTEM account: 


      Username:  SYSTEM 
  Password:  (enter your system password)

  2. Create the DLB Plus directory: 


      $ CREATE/DIRECTORY SYS$SYSDEVICE:[TTI_DLBPLUS]

    Note
    DLB Plus can be loaded into any directory on any disk...e.g., $1$WORK:[DLBPLUS])

  3. Enter the DLB Plus directory: 


      $ SET DEFAULT SYS$SYSDEVICE:[TTI_DLBPLUS]

    Note
    This directory must have the privileges READ/WRITE.

  4. Verify that you are in the new directory. You should see the message "No files found." E.g.: 


      $ DIRECTORY 
  No files found.

  5. Load instructions for CD-ROM:
    1. Put the DLB Plus distribution CD-ROM into your computer's CD drive.
    2. Make the CD drive available: 


        $ ALLOCATE DKA100: 
  $ MOUNT DKA100:/OVERRIDE=ID 
  Volume is write locked 
  DLBP mounted on _DKA100:

      Note
      "DKA100" may have to be replaced with the appropriate CD identifier for your system.

    3. Transfer DLB Plus to disk using OpenVMS BACKUP: 


        $ BACKUP/LOG DKA100:[DLB.KIT]DLB.BCK/SAVE *.*/NEW_VERSION 
  $ DISMOUNT DKA100: 
  $ DEALLOCATE DKA100:

      The transfer takes about five minutes. As DLB Plus is transferred to disk, you see a list of the files being transferred.

  6. Load instructions for tape:
    1. Put the DLB Plus distribution tape on your computer's tape drive.
    2. Make the tape drive available: 


        $ ALLOCATE MSA0: 
  $ MOUNT MSA0:/FOREIGN 
  Volume is write locked 
  DLBP mounted on _MSA0:

      Note
      "MSA0" may have to be replaced with the appropriate magtape identifier for your system.

    3. Transfer DLB Plus to disk using OpenVMS BACKUP: 


        $ BACKUP/LOG MSA0:dlb *.*/NEW_VERSION/VERIFY 
  $ DISMOUNT MSA0: 
  $ DEALLOCATE MSA0:

      The transfer takes about five minutes. As DLB Plus is transferred to disk, you see a list of the files being transferred.

  7. You can optionally start up DLB Plus or fragmentation prevention or both. During the start up procedure, informational text is displayed. This text is shown in Appendix F, An Installation Example.

    DLB Plus and Fragmentation Prevention Start Up --- To start up both DLB Plus and the fragmentation prevention feature at the same time, execute the following command: 


      $ @SYS$SYSDEVICE:[TTI_DLBPLUS]DLBPLUS_STARTUP CD

    DLB Plus Start Up --- To start up only DLB Plus, execute the following command: 


      $ @SYS$SYSDEVICE:[TTI_DLBPLUS]DLBPLUS_STARTUP

    Fragmentation Prevention Start Up --- To start up only the fragmentation prevention feature, execute the following command: 


      $ @SYS$SYSDEVICE:[TTI_DLBPLUS]DLBPLUS_STARTUP CD_ONLY

    The DLBPLUS_STARTUP procedure sets up various logicals and symbols that DLB Plus uses.
    Add one of the above commands to your system startup command procedure. Adding the command to the system startup command procedure causes DLB Plus and/or fragmentation prevention to start up each time the system is booted.

    Note
    If you have a cluster, each member of the cluster that uses DLB Plus and/or the fragmentation prevention feature must execute one of the DLBPLUS_STARTUP commands.

DLB Plus has now been installed on your computer.

If you started up DLB Plus, it will now begin to monitor the system loads and dynamically make adjustments to enhance system performance. The adjustments will be made continuously as system loads change.

3.3 DLB Plus Drivers

Note
When upgrading DLB Plus on an Alpha, you will need to reboot the system in order to reload the DLB Plus drivers.

Chapter 4
Shutting Down DLB Plus

4.1 Shutdown Instructions

To perform an orderly shutdown of DLB Plus and/or fragmentation prevention on a given node, you should log into SYSTEM and then execute the appropriate shutdown command.

DLB Plus and Fragmentation Prevention Shut Down --- This is the procedure to shut down both DLB Plus and the fragmentation prevention feature. 


    USERNAME: SYSTEM
    PASSWORD: (the system password) 
 
    $ @TTI_DLB:DLBPLUS_SHUTDOWN
    Dynamic Load Balancer Plus (Version 4.1) - DLB Plus Shutdown 
    Copyright (c) 1991-1996 Touch Technologies, Inc. 
 
    Shutting down DLB Plus... 
    DLB Plus has been shutdown 
    Shutting down CleanDisk... 
    CleanDisk has been shutdown 
    DLB Plus shutdown process has completed 
 
    $ LOGOUT

DLB Plus Shut Down --- This is the procedure to shut down only DLB Plus: 


    USERNAME: SYSTEM
    PASSWORD: (the system password) 
 
    $ @TTI_DLB:DLBPLUS_SHUTDOWN DLB_ONLY
    Dynamic Load Balancer Plus (Version 4.1) - DLB Plus Shutdown 
    Copyright (c) 1991-1996 Touch Technologies, Inc. 
 
    Shutting down DLB Plus... 
    DLB Plus has been shutdown 
    DLB Plus shutdown process has completed 
 
    $ LOGOUT

Fragmentation Prevention Shut Down --- This is the procedure to shut down only fragmentation prevention: 


    USERNAME: SYSTEM
    PASSWORD: (the system password) 
 
    $ @TTI_DLB:DLBPLUS_SHUTDOWN CD_ONLY
    Dynamic Load Balancer Plus (Version 4.1) - DLB Plus Shutdown 
    Copyright (c) 1991-1996 Touch Technologies, Inc. 
 
    Shutting down CleanDisk... 
    CleanDisk has been shutdown 
    DLB Plus shutdown process has completed 
 
    $ LOGOUT

Previous Next Contents Index