This section describes QLogic adapter settings that can be changed
based on the kernel, distribution, and IBM server hardware that you are attaching
to the DS6000™.
It also describes modifications to configuration parameters that you can change
if you receive errors when you are running the Linux operating system on an
Intel host that is attached with a QLogic adapter.
Before you proceed, determine the kernel version of the
Linux distribution that you running.
Type the uname -r command
to display the kernel version that you are running.
The output displays
2.4.x or 2.6.x, where x represents the maintenance and
fix level for the installed distribution.
For multipath solutions that
use an IBM SDD, you must disable the QLogic failover mechanism. Complete these
steps to disable the failover mechanism.
- If the driver version has a <version> -fo extension,
the failover driver is currently installed and you must disable the driver.
If the driver is not installed, you do not need to complete these steps.
- For 2.4 kernels, edit the /etc/modules.conf file. For 2.6
kernels, edit the /etc/modprob.conf or /etc/modprob.conf.local file.
- Add the following line to the file: options qla2xxx qla2xfailover=0
For host systems that will be performing remote mirror
and copy or Flash Copy functions, modify the timeout values to prevent I/O
errors from occurring. The qfull_retry_count option (available
for 2.4 kernels only) defines the number of times that a QLogic adapter
card retries a command if the queue is full. The default for this option is
16.
Perform the following steps to increase the timeout value
to 32.
- For 2.4 kernels, edit /etc/modules.conf. For 2.6 kernels,
edit /etc/modprobe.conf or /etc/modprob.conf.local.
- If the value of the qfull_retry_count option is not 32,
change it to 32 and save the configuration file. If the option does not exist,
add the following line: options qla2xxx qfull_retry_count=32.
- Use your normal procedure to reload the driver settings. For example,
use the host system command modprobe -r to remove the driver
and use the modprobe command to install the driver.
Note: If your QLogic driver loads at system start, run the mkinitrd command
to build a new ramdisk device to reflect this change. Also run the zipl utility
to update the initial program load record to point to the new ramdisk device.