Open main menu

OpenVZ Virtuozzo Containers Wiki β

Changes

UBC secondary parameters

2,532 bytes added, 13:56, 22 August 2006
more params added (still work in progress)
by the hardware resources of the system.
This total limit is discussed in [[UBC systemwide configuration#“Low memory”|“low memory”]].
 
== othersockbuf ==
The total size of buffers used by local (UNIX-domain) connections between
processes inside the system (such as connections to a local database server)
and send buffers of UDP and other datagram protocols.
 
<code>Othersockbuf</code> parameter depends on number of non-TCP sockets (<code>[[numothersock]]</code>).
 
<code>Othersockbuf</code> configuration should satisfy
 
<math>othersockbuf_{lim} - othersockbuf_{bar} \ge 2.5KB \cdot numothersock</math>
 
Increased limit for <code>othersockbuf</code> is necessary for high performance of
communications through local (UNIX-domain) sockets.
However, similarly to <code>tcpsndbuf</code>, hitting <code>othersockbuf</code> affects
the communication performance only and does not affect the functionality.
 
<code>Othersockbuf</code> limits can't be set arbitrarily high.
The total amount of <code>othersockbuf</code> consumable by all Virtual Environments
in the system plus the <code>kmemsize</code> and other socket buffers
is limited by the hardware resources of the system.
This total limit is discussed in [[UBC systemwide configuration#“Low memory”|“low memory”]].
 
== dgramrcvbuf ==
The total size of buffers used to temporary store the incoming packets of UDP and
other datagram protocols.
 
<code>Dgramrcvbuf</code> parameters depend on number of
non-TCP sockets (<code>[[numothersock]]</code>).
 
<code>Dgramrcvbuf</code> limits usually don't need to be high.
Only if the Virtual Environments needs to send and receive very large
datagrams, the <code>barrier</code>s for both <code>othersockbuf</code> and
<code>dgramrcvbuf</code> parameters should be raised.
 
Hitting <code>dgramrcvbuf</code> means that some datagrams are dropped, which may
or may not be important for application functionality.
UDP is a protocol with not guaranteed delivery, so even if the buffers
permit, the datagrams may be as well dropped later on any stage of the
processing, and applications should be prepared for it.
 
Unlike other socket buffer parameters, for <code>dgramrcvbuf</code>
the <code>barrier</code> should be set to the <code>limit</code>.
 
<code>Dgramrcvbuf</code> limits can't be set arbitrarily high.
The total amount of <code>dgramrcvbuf</code> consumable by all Virtual Environments
in the system plus the <code>kmemsize</code> and other socket buffers
is limited by the hardware resources of the system.
This total limit is discussed in [[UBC systemwide configuration#“Low memory”|“low memory”]].
 
== oomguarpages ==
FIXME
 
== privvmpages ==
FIXME