INF: LM0420: Setting Up Disk Mirroring in OS/2 LAN Manager

ID Number: Q76258

2.00

OS/2

Summary:

The application note below describes how to set up disk mirroring on

an OS/2 LAN Manager version 2.0 machine.

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LM0420: SETTING UP DISK MIRRORING IN OS/2 LAN MANAGER

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Revision Date: 7/91

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| Copyright 1991 Microsoft Corporation. All Rights Reserved. |

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Introduction

============

This application note describes a step-by-step procedure for setting

up disk mirroring on an OS/2 LAN Manager version 2.0 machine.

Before beginning this procedure, it is important to note that the disk

device driver, either DISK01.SYS (ISA or EISA bus) or DISK02.SYS (MCA

bus), must support fault tolerance. If you have a question as to

whether your hard disk drive is supported, contact LAN Manager Product

Support.

Setting Up Mirroring

====================

1. From the Desktop Manager's Utilities menu, choose the PM fixed disk

utility (PMFDISK). Two drive icons should be present below the

action bar indicating that a physical disk 1 and a physical disk 2

exist on the machine. Two physical drives are required for both

disk mirroring and duplexing (duplexing also requires a second

controller).

2. Check the type, size, and percentage of the disk space used by the

first partition of physical disk 1. If the percentage of disk space

being used is 100 percent or the type is FAT, go to step 3;

otherwise, go to step 4.

3. OS/2 version 1.21 does not allow the primary partition of a

machine's boot drive (physical disk 1) to be mirrored, nor will it

mirror FAT partitions. If either of these two cases is true of your

system, you must repartition your boot drive by performing the

following steps:

a. Back up all essential files to disk or tape.

b. Boot off the OS/2 installation floppy disk. Press the ESC key at

the initial screen. Type "fdisk /d" (without the quotation

marks) and respond with "Y" to the question that is displayed.

Note: This step is essential because after OS/2 has been

installed the first time, all future installations of OS/2

will use the same partition size. You will not be prompted

to change the size unless you are installing OS/2 for the

first time, or unless the primary partition has been

deleted prior to the installation.

c. Reinstall OS/2, being careful to select a primary partition that

is smaller than the whole of physical disk 1 (leave about 25 MB

of disk space available for this partition for both OS/2 LAN

Manager and OS/2, unless the SWAPPER.DAT file is redirected

elsewhere). Choose Yes when prompted to format the partition as

HPFS.

4. Once the partition sizes are set correctly, start the PM fixed disk

utility and create an extended partition on primary disk 1. DO NOT

create a logical drive for this partition.

5. Select physical drive 2 and create a primary and extended partition

that matches the first physical drive. DO create a logical drive

for this partition. The drives should now look like the following:

Drive 1

-------

Partition Information

Partitions Status Type Size in Percent of Disk

MBytes

---------- ------ ---- ------- ---------------

C: Startable HPFS XX XX%

Not Startable EXT OS/2 YY YY%

Drive 2

-------

Partition Information

Partitions Status Type Size in Percent of Disk

MBytes

---------- ------ ---- ------- ---------------

D: Not Startable PRI OS/2 XX XX%

Not Startable EXT OS/2 YY YY%

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Logical Drive Information

E: YY YY%

If drive D reads HPFS or FAT rather than PRI OS/2, it means that

the primary partition has been formatted. Exit the PM fixed disk

utility and reboot to have the partition changes take effect.

6. Run Ftsetup from an OS/2 command prompt. From the Config menu,

choose Mirror Drive(s). Select logical drive E and respond

affirmatively to all the OK prompts. Reboot the computer when the

following message appears:

Changes have been made to the disk partition table. You must

restart the computer for these changes to take effect.

7. If everything is correct, Ftsetup will automatically be loaded from

the STARTUP.CMD file during the system boot and will prompt you to

format logical drive E. Choose OK. Verify the drive status with the

View Drive Status command (on the Config menu). Exit Ftsetup and

the STARTUP.CMD file will proceed normally. Ftsetup is

automatically REMarked out after the STARTUP.CMD file completes.

8. Disk mirroring setup is now complete. The drives will now mirror in

the following direction:

+---------+ +---------+

| | | |

| c | | d |

| | | |

| | | |

|---------| |---------|

| | | |

| Mirror |<-----| e |

| | | |

| | | |

+---------+ +---------+

Additional reference words: 2.00