User`s guide

Managing Resources 105
Turning On and Off Network Bandwidth Management
Traffic shaping also known as network bandwidth management allows you to control what
network bandwidth a Container receives for outgoing traffic. Traffic shaping is off by default in
Parallels Server Bare Metal and is controlled by the TRAFFIC_SHAPING variable in the
/etc/vz/vz.conf global configuration file.
Note: Container incoming traffic cannot be controlled in Parallels Server Bare Metal.
To turn traffic shaping on, you need to complete the following steps:
 Set the value of TRAFFIC_SHAPING to yes in the global configuration file.
 Correctly set up the BANDWIDTH and TOTALRATE parameters values.
 Start traffic shaping with the /etc/init.d/vz shaperon command.
The BANDWIDTH variable is used for specifying the network rate (in kilobits per second) of
available network adapters. By default, it is set to eth0:102400, which corresponds to a
100Mb/s Fast Ethernet card. If your server has more network adapters installed, you need to
update this variable to list all the adapters participating in shaping. For example, in case of two
Fast Ethernet cards this variable shall be set to eth0:102400 eth1:102400.
The TOTALRATE variable specifies the size of the so-called bandwidth pool for each network
class being shaped. The bandwidth from the pool can be borrowed by Containers when they
need more bandwidth for communicating with hosts from the corresponding network class. It is
used to limit the total available outgoing traffic Containers can consume; the next section
explains it in more detail. The format of this variable is
<NIC>:<network_class>:<bandwidth_in_Kbits_per_second> and defines the
pool size per network class for a given network adapter. Multiple entries for different network
classes and adapters shall be separated by spaces. The default value for TOTALRATE is
eth0:1:4096, which corresponds to the pool size of 4Mb/s for Network Class 1 on the first
Ethernet adapter.
In the /etc/vz/vz.conf configuration file, you can also define the RATE variable whose
value amounts to the number of kilobits per second any Container is guaranteed to receive for
outgoing traffic with a network class on an Ethernet device. The default value of this parameter
is eth0:1:8, which means that any Container is guaranteed to receive the bandwidth of at
least 8 Kb/s for sending data to Class 1 hosts on the first Ethernet device. This bandwidth is not
the limit for a Container (unless the RATEBOUND parameter is set to yes in the Container
configuration file) – the Container is able to take the needed bandwidth from the TOTALRATE
bandwidth pool if it is not used by other Containers.
After setting up the above variables, start bandwidth management as follows:
# /etc/init.d/vz shaperon
Starting shaping: Ok
Set shaping on running Container :
vz WARNING: Can't get tc class for Container(101).
vz WARNING: Can't access file /var/run/vz_tc_classes. \
Creating new one.
vz WARNING: Can't get tc class for Container(1).