HP A6829A PCI Dual Channel Ultra160 SCSI Host Bus Adapter Service and User Guide (May 2003)

Installing the A6829A Adapter

Chapter 2 19

Adapter Compatibility

This section explains adapter compatibility considerations for

performing OLA and OLR.

Online Addition (OLA) You can add multiple adapters at the same

time. While adding an adapter online, the ﬁrst issue you must resolve is

whether the new adapter is compatible with the system. Each

OLAR-capable PCI slot provides a set amount of power. The replacement

adapter cannot require more than the available power.

The adapter must also operate at the slot’s bus frequency. A PCI adapter

must run at any frequency lower than its maximum capability, but an

adapter that could operate at only 33 MHz would not work on a bus

running at 66 MHz. The SCSI A6829A HBA operates at 66MHz. The rad

command provides information on the bus frequency and power available

at a slot, as well as other slot-related data.

If your system has one or more slots that support OLAR, and you want to

use OLA to install the A6829A in one of those slots, install the adapter in

your HP-UX system according to the procedure described in the

“Managing PCI Cards with OLAR” chapter of the Conﬁguring HP-UX

Peripherals manual.

After you add a new A6829A adapter, SAM tries to locate the SCSI c8xx

driver. If SAM is unable to locate the driver, you cannot use the new

adapter until you install the driver (remember that driver installation

requires a system reboot). If SAM locates the driver, it determines

whether the new adapter is functional. If the adapter is not functional,

SAM displays an error message.

Online Replacement (OLR) While replacing an interface adapter

online, the replacement adapter must be identical to the adapter being

replaced, or at least be able to operate using the same driver as the

replaced adapter. This is referred to as like-for-like replacement and

should be adhered to, because using a similar but not identical adapter

can cause unpredictable results.

For example, a newer version of the target adapter that is identical to the

older adapter in terms of hardware might contain an updated ﬁrmware

version that could potentially conﬂict with the current driver. In

addition, the old adapter and new adapter must have the same PCI

identiﬁers (subsystem ID and device ID).