16
Figure 6.
Turning on NTP using the XenServer xsconsole
Network configuration and bonding
Network traffic to XenServer hosts may consist of the following types:
XenServer management
VM LAN traffic
iSCSI SAN traffic
Although a single physical network adapter can accommodate all these traffic types, its bandwidth
would have to be shared by each. However, since it is critically important for iSCSI SRs to perform
predictably when serving VM storage, it is considered a best practice to dedicate a network adapter
to the iSCSI SAN. Furthermore, to maximize the availability of SAN access, you can bond multiple
network adapters to act as a single interface, which not only provides redundant paths but also
increases the bandwidth for SRs. If desired, you can create an additional bond for LAN connectivity.
Note
XenServer supports source-level balancing (SLB) bonding.
It is a best practice to ensure that the network adapters configured in a bond have matching physical
network interfaces so that the appropriate failover path can be configured. In addition, to avoid a
SPOF at a common switch, multiple switches should be configured for each failover path to provide
an additional level of redundancy in the physical switch fabric.
You can create bonds using either XenCenter or the XenServer console, which allows you to specify
more options and must be used to set certain bonded network parameters for the iSCSI SAN. For
example, the console must be used to set the
disallow-unplug
parameter to
true
.
