To start using a channel board (25-Gbps iSCSI optical), enable the setting for retrying I/O when all paths fail, so that I/O continues even when the channel board (25-Gbps iSCSI optical) fails. Enable the setting for retrying I/O when all paths fail, only in the channel board (25-Gbps iSCSI optical) environment.
The setting for retrying I/O when all paths fail retries I/O on the failed paths when a failure occurs on all paths and retries I/O again after the specified wait time has elapsed.
To start using the channel board (25-Gbps iSCSI optical), set the number of I/O retries and the wait time, so that the total wait time equals 150 seconds#.
If you increase the number of retries, the I/O load on the system increases. You can reduce the I/O load by increasing the wait time after each retry. However, if you increase the wait time, the path recovery time will be delayed. Set the value according to your environment.
Run the dlmsetopt utility for setting HDLM driver options. Run the command in two steps.
The following example shows how to set the number of retries to 30 and the waiting time to 5 seconds. The settings are specified so that the total wait time is 150 seconds (30 retries x 5 seconds).
For details on the dlmsetopt utility for setting HDLM driver options, see dlmsetopt utility for setting HDLM driver options.
# /opt/DynamicLinkManager/bin/dlmsetopt -epr 30 KAPL12554-I The utility for setting HDLM driver option has started. KAPL12555-I The utility for setting HDLM driver option completed normally. KAPL12558-I Please restart the computer so that the option settings take effect. # /opt/DynamicLinkManager/bin/dlmsetopt -epd 5 KAPL12554-I The utility for setting HDLM driver option has started. KAPL12555-I The utility for setting HDLM driver option completed normally. KAPL12558-I Please restart the computer so that the option settings take effect. #
Restart the host.
# shutdown -r now