Developers Guide

Server configuration
43 Dell EMC SC Series with Red Hat Enterprise Linux 7x | CML1071
ports experiencing failure will be relocated to the active NPIV ports within the same fault domain on the
alternate active controller.
In order to mitigate I/O disruption in single-pathed scenarios, instruct the HBA driver code to wait up to 60
seconds before marking a port as down or failed. This allows the SC Series storage sufficient time to relocate
the WWPN of the failed ports to active ports and to propagate the changes through the SAN fabric. The
configuration syntax for a single path environment is shown in the following subsections.
3.8.1 PortDown timeout
These settings dictate how long a Linux system waits before destroying a connection after losing its
connectivity with the port. Configure the following in the qla2xxx.conf or lpfc.conf file accordingly.
 For QLogic:
options qla2xxx qlport_down_retry=60
 For Emulex:
options lpfc lpfc_devloss_tmo=60
3.8.2 Verifying parameters
To verify that the configuration changes have taken effect, apply the following commands.
 For QLogic:
# cat /sys/module/qla2xxx/parameters/qlport_down_retry
60
 For Emulex:
# cat /sys/class/scsi_host/hostX/lpfc_devloss_tmo
60