User`s guide

Managing Resources 112
SLM Modes
SLM is automatically enabled during the Parallels Server Bare Metal installation on the server,
i.e. you do not have to perform any additional operations to start using this functionality on your
server. After the installation, you can manage SLM in one of the following ways:
 Disable SLM on a global basis. In this case no Container on the server will be able to make
use of this functionality. To disable SLM, complete the following tasks:
 Specify no as the value of the SLM parameter in the /etc/vz/vz.conf global
configuration file.
 Reboot the server:
# shutdown -r now
 Control the SLM mode for a particular Container on the server. The current version of
Parallels Server Bare Metal allows you to set one of the following SLM modes for your
Container:
 limited mode. In this mode, the SLM functionality for the corresponding Container is
enabled and can be used to control the 'total' and 'low' memory consumption by all
Containers on the server, which prevents the memory from being overused and
guarantees the reliable performance of the server. At the same time, you can use various
UBC parameters to manage particular resources of the Container. If the Container does
not have any UBC parameters set, SLM also undertakes the control over the
consumption of these resources by this Container. By default, any Container created is
functioning in the limited mode. If your Container is working in another mode, you can
return it to this mode by executing the pctl set command and passing the --
slmmode all option to it.
 full mode. In this mode, the SLM functionality for the corresponding Container is
enabled and can be used to the full extent for managing the amount of memory which
can be allocated to and consumed by the Container. Enabling the full mode automatically
sets the values of all UBC parameters to unlimited. When functioning in this mode, SLM
may significantly improve the resources allocation among individual Containers. For
example, it allows you to avoid situations when the memory allocation for some
application inside the Container fails although the system has a lot of free resources. The
full mode can be set by using the --slmmode slm option with the pctl set
command.
 compatibility mode. In this mode, the SLM functionality for the corresponding Container
is disabled and the system resources control management is performed by using UBC
parameters only: numproc, numtcpsock, numothersock, vmguarpages,
kmemsize, etc. Detailed information on all UBC parameters is provided the
Administrator's Guide to Managing UBC Resources guide available at
http://www.parallels.com/products/virtuozzo/docs/. The compatibility mode can be set
by using the --slmmode ubc option with the pctl set command.
Note: You can also enable any of the aforementioned modes by editing the Container
configuration file and setting the corresponding value (all, slm, or ubc, respectively) of
the SLM parameter in this file.