March 2013
Dell EqualLogic Configuration Guide v14.1
2-24
2.3.4
Storage Heartbeat on vSphere 5.0, 4.1, and 4.0
Note:
This recommendation for using Storage Heartbeat applies only vSphere 4.1 and
5.0. It is not necessary with vSphere 5.1.
In the VMware virtual networking model, certain types of vmkernel network traffic is sent out on a
default vmkernel port for each subnet. If the physical NIC that is being used as the uplink for the
default vmkernel port goes down, network traffic that is using the default vmkernel port will fail,
including vMotion traffic, SSH access, and ICMP ping replies.
Even though iSCSI traffic is not directly affected by this condition, a side effect of the suppressed ping
replies is that the EqualLogic PS Series Group will not be able to accurately determine connectivity
during the login process, and therefore a suboptimal placement of iSCSI sessions can occur. This
could cause logins to not be completed in a timely manner.
It is recommended to have a high availability vmkernel port on the iSCSI subnet serving as the
default vmkernel port for such outgoing traffic.
2.3.5
Linux servers
The HIT Kit for Linux automatically implements recommended changes on the Linux hosts,
either at the time of installation or through the built-in “eqltune” utility
2.3.6
Network topology health check
Design your network for redundancy according to recommended best practices:
•
For all members (arrays) in a given SAN Group all ports should be connected to the same subnet.
•
Use at least two iSCSI SAN ports per host connected, so that at least two of the host ports connect
to two different switches in the SAN
•
At a minimum Eth0 from Controller0 and Controller1 on each array in the SAN group must be
connected to two different switches in the same SAN subnet.
•
All switches within the SAN must be interconnected such that there is always a path from any
Ethernet port on one array to all other Ethernet ports on all other arrays in the group.
Proper settings configured on switches:
•
All switches and host network controllers within the infrastructure must have flow control enabled
for optimal performance. For switches, RX flow control is required. For iSCSI hosts, both TX and
RX is required.
•
Rapid Spanning Tree must be enabled on all switch ports not directly connected to host or array
ports.
•
Enable PortFast on all switch ports connected to the host or array ports.
See section 7 for complete iSCSI SAN design recommendations.
2.3.7
Environmental health
Verify there are no current health and/or performance problems with the EqualLogic environment.
