Microsoft KB Archive/67605

Understanding Hard Disk Support in OS/2 and OS/2 LAN Manager ID Number: Q67605

2.00 OS/2

Summary:

Included with OS/2 version 1.21 are two hard disk drive device drivers named DISK01.SYS and DISK02.SYS. DISK01.SYS is designed to support ISA and EISA Bus architectures, and DISK02.SYS is designed to support the MCA bus.

OS/2 LAN Manager version 2.00 ships an extended version of these drivers that provides the additional ability to do FT (fault tolerance) (that is, disk mirroring and disk duplexing) and local security. To support their own kinds of hard disk devices, many OEM OS/2 vendors ship their own version of these device drivers. Most OEMs, however, do not include the code necessary to do OS/2 LAN Manager fault tolerance and local security. As such, if your OEM or hard drive manufacturer requires that you use a specific hard disk device driver, you probably will not be able to run fault tolerance or local security on your OS/2 LAN Manager machine.

If your system matches the scenario above, DO NOT choose the option to install the extended DISK01.SYS or DISK02.SYS drivers during the OS/2 LAN Manager Setup.

More Information:

In the PC environment, there are three major bus architectures (ISA, EISA, and MCA) and six major hard disk drive types (RLL, SCSI, MFM, IDE, and ESDI) that run on these architectures. For a bus to be able to understand a particular hard disk drive type, your machine must have a hard disk drive controller card that can use both the bus and the drive type.

For example, a SCSI hard disk drive can run on an ISA, EISA, or MCA bus as long as the hard disk drive controller card can communicate with both the bus and the hard disk drive.