Developers Guide

Server configuration
32 Dell EMC SC Series with Red Hat Enterprise Linux 7x | CML1071
3.2.3 Configuring /etc/fstab
iSCSI is dependent on an operational network, and volumes added to /etc/fstab need to be designated as
network-dependent. In other words, do not attempt to mount an iSCSI volume until the network layer services
have completed the startup and the network is operational. The example below demonstrates how to create
this network dependency to the iSCSI mount using the _netdev mount option in the /etc/fstab file.
# cat /etc/fstab
[snip]
/dev/mapper/VolGroup00-home /home xfs defaults 1 2
/dev/mapper/VolGroup00-swap swap swap defaults 0 0
LABEL=iSCSI_Vol /mnt/iSCSI_Vol ext4 defaults,_netdev 0 0
[snip]
3.3 Serial-attached SCSI
The Dell SCv2000 Series product line offers serial-attached SCSI (SAS) front-end connectivity and coincides
with the launch of SCOS 6.6.x. The Dell SCv2000 Series supports the use of Dell EMC 12Gbps SAS HBAs
on the target hosts.
SAS connectivity to a Linux host requires specific configuration schema in the /etc/multipath.conf file.
3.3.1 SAS drivers
SAS drivers are preloaded into certain Linux kernels (RHEL 6.5 or newer, and RHEL 7.x). The existence of
the SAS drivers can be validated with the following commands. As a best practice, validate the driver versions
with the Dell EMC Storage Compatibility Matrix and use the latest supported driver as indicated.
# lsmod | grep sas
mpt3sas 188001 4
scsi_transport_sas 35588 1 mpt3sas
raid_class 4388 1 mpt3sas
megaraid_sas 96205 2
# modinfo mpt3sas | grep description
description: LSI MPT Fusion SAS 3.0 Device Driver