Installing the A6828A Adapter

This section contains information on installing the A6828A HBA in an HP-UX system (including Online Addition and Replacement [OLAR]).




	WARNING! The installation procedures in this section require opening the computer cabinet, which might expose you to high-energy (high-amperage) circuits and sharp edges in the equipment chassis. Ensure to remove all rings, watches, and other jewelry before opening the cabinet.




	CAUTION: The A6828A adapter contains electronic components that can easily be damaged by small amount of static electricity. To avoid damage, follow these guidelines: Store the adapter in its antistatic plastic bag until you are ready to install it. Work in a static-free area, if possible. Handle the adapter by the edges only. Do not touch electronic components or electrical traces. If you must lay the adapter down, place it on a non-conductive mat or surface. Use the ESD kit that is provided with the adapter. Follow the instructions included with the kit. Use a suitable ground—any exposed metal surface on the system chassis.

Before beginning the installation, and without removing the adapter from its antistatic bag, inspect the adapter for any signs of obvious damage, such as chipped or loose components. Contact Hewlett-Packard if the adapter is damaged.

Install the A6828A HBA in your HP-UX system according to the documentation for the system.




	NOTE: As stated earlier, although the A6828A HBA is supported on only 64-bit HP-UX 11.0 and 11i, you can install the adapter in either a 32-bit or 64-bit PCI slot. In addition, HP recommends using a PCI4X or PCI2X slot, to get maximum performance. However, you can install the adapter in a PCI2X, PCI1X, or shared PCI slot, if necessary.

When you have finished installing the A6828A HBA, go to section “Connecting External SCSI Peripherals”.

Online Addition and Replacement—HP-UX 11i Only

Online Addition and Replacement (OLAR) is the ability of a PCI host bus adapter to be replaced in or added to an HP-UX system designed to support this feature, without the need for completely shutting down and then rebooting the system or adversely affecting other system components. The system hardware uses the per-slot power control combined with OS support to enable this feature.

Check the latest SCSI support matrix that contains information on the HP-UX systems that support OLAR of the A6828A adapter. The support matrix is available at http://docs.hp.com under the Networking and Communications section.




	IMPORTANT: Certain “classes” of hardware are not intended for access by users. At this time, this includes superdome systems. HP recommends that these systems be opened by a qualified HP engineer only. Failure to observe this requirement can invalidate any support agreement or warranty to which the owner might otherwise be entitled.

You can add or replace an OLAR-compatible adapter in either of the following ways:

Using the SAM utility.
Issuing command-line commands, through rad, that refer to the c8xx OLAR script (/usr/sbin/olard.d/c8xx).

HP recommends that you use SAM instead of the rad command to perform OLAR procedures. This is because for the most part, SAM prevents you from performing OLAR procedures that would adversely affect other areas of the system. This is not true when you use the rad command.

For detailed information on using either of these two procedures, see Configuring HP-UX For Peripherals. You can order that document from Hewlett-Packard, or you can view, download, and print it from http://www.docs.hp.com.

Table 2-1 “Important OLAR Terms” below explains some important OLAR-related terms.

Table 2-1 Important OLAR Terms

Term	Meaning
OLAR	All aspects of the OLAR feature, including Online Addition (OLA) and Online Replacement (OLR).
Power Domain	A grouping of one or more interface adapter slots that are powered on or off as a unit. (Note: Currently, multi-slot power domains are not supported.)
target adapter / target adapter slot	The interface adapter that will be added or replaced using OLAR, and the adapter slot it is in.
affected adapter / affected adapter slot	Interface adapters and the adapter slots they are in, and which are in the same power domain as the target slot.




	IMPORTANT: In many cases, other interface adapters and slots within the system are dependent on the target adapter. For example, if the target adapter is a multiple-channel adapter, suspending or deleting drivers for the target adapter slot also suspends individual drivers for the multiple hardware paths on that adapter.

During an adapter replacement operation, SAM performs a Critical Resource Analysis (CRA), which checks all channels on the target adapter for critical resources that will be temporarily unavailable while the adapter is shut down.

Planning and Preparation

As mentioned earlier, for the most part, SAM prevents you from performing OLAR procedures that would adversly affect other areas of the HP-UX system. See Configuring HP-UX For Peripherals for detailed information.

Critical Resources

Replacing an adapter that is still operating can have adverse consequences. As power to the slot must be off when the old adapter is removed and the new adapter is inserted, you must consider the effects of shutting down the adapter’s functions.

This is particularly important if no online failover or backup adapter to pick up those functions is installed. For example:

Which mass storage devices will be temporarily disconnected when the adapter is shut down?
Will a critical networking connection be lost?

A critical resource is one that would cause a system crash or prevent the operation from completing successfully if the resources were temporarily suspended or disconnected. For example, if the SCSI adapter to be replaced connects to the unmirrored root disk or swap space, the system will crash when the adapter is shut down.

During an OLAR procedure, it is essential to check the targeted adapter for critical resources, as well as the effects of existing disk mirrors and other situations where an adapter’s functions can be taken over by another adapter that will not be affected.

As mentioned earlier, SAM performs a thorough CRA automatically, and presents options based on its findings. If you determine that critical resources will be affected by the procedure, you can replace the adapter when the system is offline. On the other hand, if you are required to take an action immediately, you can use the rad command to try an online addition of a backup adapter and deletion of the target adapter.

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 A6828A 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 A6828A 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 A6828A 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).

The PCI specification allows a single physical adapter to contain more than one channel. A single channel SCSI adapter cannot be replaced by a dual channel adapter, even if the additional channel(s) on the adapter are identical to the original SCSI adapter.

When the replacement adapter is added to the system, the appropriate driver for that adapter must be configured in the kernel before beginning the replacement operation. SAM ensures the correct driver is present. (In most cases, the replacement adapter will be of the same type as an adapter already in the system, and this requirement will be automatically met.) Keep the following things in mind:

If the necessary driver is not present and the driver is a dynamically loadable kernel module (DLKM), you can load it manually. See the section “Dynamically Loadable Kernel Modules” in Configuring HP-UX For Peripherals for more information.
If the driver is static and not configured in the kernel, then the adapter cannot be added online. The adapter could be physically inserted online, but no driver will claim it. Note that the SCSI c8xx driver is a static driver.

If you have any question about the driver’s presence, or if you are not certain that the replacement adapter is identical to the existing adapter, you can use the ioscan command together with the rad command to investigate.

SAM does not allow the A6828A HBA to be suspended in either of the following situations:

If the adapter is being used (for example, if a file system is mounted).
If the CRA shows that a critical resource (for example, swap space or the root file system) depends on the adapter.

After you replace an A6828A adapter online, SAM checks the replacement adapter to make sure it is permitted, according to the like-for-like rules. If the adapter is permitted, SAM automatically activates it. If it is not permitted, SAM displays an error message.

Installing the A6828A Adapter

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