Information Technology Reference
In-Depth Information
The mechanisms used to select one link or another are fundamentally the following:
A NIC teaming/link aggregation choice, which is set up per TCP connection and is either
static (set up once and permanent for the duration of the TCP session) or dynamic (can be
renegotiated while maintaining the TCP connection, but still always on only one link or
the other).
◆
A TCP/IP routing choice, where an IP address (and the associated link) is selected based on
layer 3 routing—note that this doesn't imply that trafi c crosses subnets via a gateway, only
that the ESXi host selects the NIC or a given datastore based on the IP subnet.
◆
Figure 6.45 shows the basic decision tree.
Figure 6.45
h e choices to con-
fi gure highly avail-
able NFS datastores
depend on your net-
work infrastructure
and confi guration.
Do my switches
support multi-
switch link
aggregation?
Yes
No
Configure two or more VMkernel
ports on different subnets.
Configure one VMkernel port.
Configure vSwitch to use
link aggregation.
Configure vSwitch not to use
link aggregation.
To use multiple links,
use IP
hash (source/dest) load
balancing policy;
use
VMkernel routing table
(separate subnets);
To use multiple links,
requires
multiple datastores.
requires
multiple datastores.
Configure NFS server to have
multiple IP addresses;
Configure NFS server to have
multiple IP addresses;
can be on
the same subnet.
must be
on different subnets.
Configure switch-NFS server link
to be consistent with ESXi
host settings.
The path on the left has a topology that looks like Figure 6.46. Note that the little arrows
mean that link aggregation/static teaming is coni gured from the ESXi host to the switch and
on the switch to the ESXi host; in addition, note that there is the same setup on both sides for the
relationship between the switch and the NFS server.
