FibrChanl-01 (fcd) Fibre Channel Mass Storage Driver for HP-UX 11i v2 Release Notes, Version B.11.23.03

FibrChanl-01 (fcd) Fibre Channel Mass Storage Driver for HP-UX 11i v2 Release Notes

Known Problems and Workarounds and Recommendations

Chapter 1

Using ioscan with krm Not Running

A general issue when using ioscan when krm (kernel resource monitor) is not running.

Issue

When ioscan is run with the -fn or -Fn option and kernel resource monitor (krm) is not running, there could

be stale krm device ﬁles in the system which would correspond to different devices, including fcd, in ioscan

output. This issue has no impact on the functionality of the Fibre Channel port, however, ioscan output may

be confusing. This issue can impact any card accessible with ioscan and is not speciﬁc to the cards supported

by the fcd driver.

Workaround

The ioscan output can be returned to normal by either deleting the stale krm device ﬁles, or by starting krm,

which will recreate the device ﬁles.

Increased Boot Time with Unconnected fcd HBA Ports

The following is a problem which may occur on Fibre Channel ports controlled by the fcd driver.

Issue

System boot time will be increased if there are unconnected FCD HBA ports (i.e. HBA ports controlled by the

fcd driver).

This happens because an ioscan is performed as a part of the boot process for HP-UX. When an ioscan is

performed for the ﬁrst time for a FCD HBA port, the fcd driver waits for 21 seconds for the port to come online

if it is not already online. Hence, for every unconnected port the driver waits for 21 seconds before declaring

the port as ofﬂine.

This is only an issue during boot, because at boot time the HBA ports are scanned sequentially. After boot, the

HBA ports are scanned in parallel using kernel threads.

The delay observed during boot will be around N*21 seconds, where N is the number of unconnected FCD

HBA ports.

Workaround

Two workarounds are available for this issue:

• Attach loop back hoods to all of the unconnected HBA ports. The loop back hoods will cause the

unconnected HBA ports to come online in a private loop topology.

• Install the product bundle, mtIOScan, that enables boot time kernel threads. This will reduce the overall

boot delay due to unconnected ports to 21 seconds. This product can be obtained from