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| − | {{UBC toc}} | + | {| class="wikitable" |
| − | | + | ! Name !! Description |
| − | All the existing parameters are listed in the [[UBC parameters table]].
| + | |- |
| − | | + | | colspan="2" align="center" | Primary parameters |
| − | By importance, the parameters are divided into 3 groups: [[UBC primary parameters|primary parameters]],
| + | |- |
| − | [[UBC secondary parameters|secondary parameters]] and [[UBC auxiliary parameters|auxiliary parameters]].
| + | | numproc || Number of processes and threads. |
| − | More detailed description of the parameters and the resource control
| + | |- |
| − | mechanisms governed by the parameters is provided in the appropriate articles.
| + | | numtcpsock || Number of TCP sockets. |
| − | | + | |- |
| − | == General information about all parameters ==
| + | | numothersock || Number of sockets other than TCP. |
| − | All resource control parameters have some common properties
| + | |- |
| − | and some differences.
| + | | vmguarpages || Memory allocation guarantee, in pages. |
| − | | + | |- |
| − | <ol>
| + | | colspan="2" align="center" | Secondary parameters |
| − | <li>Most parameters provide both accounting of some system resource
| + | |- |
| − | and allow controlling its consumption.
| + | | kmemsize || Size of unswappable kernel memory, allocated for processes in this [[VE]]. |
| − | The exceptions are <code>physpages</code> (accounting only)
| + | |- |
| − | and <code>vmguarpages</code> (no accounting, control only), explained below.</li>
| + | | tcpsndbuf || Total size of TCP send buffers. |
| − | | + | |- |
| − | <li>Each parameter has 2 configuration variables, called <code>barrier</code> and <code>limit</code>.
| + | | tcprcvbuf || Total size of TCP receive buffers. |
| − | | + | |- |
| − | Although both 2 variables are changeable, only one or none of them may be
| + | | othersockbuf || Total size of UNIX-domain socket buffers, UDP and other datagram protocol send buffers. |
| − | effectively used for the resource control for some parameters.
| + | |- |
| − | For example, <code>physpages</code> is an accounting-only parameter and both its
| + | | dgramrcvbuf || Receive buffers of UDP and other datagram protocols. |
| − | configuration variables are not effectively used in the current OpenVZ
| + | |- |
| − | version.
| + | | oomguarpages || The guaranteed amount of memory for the case the memory is “over-booked” (out-of-memory kill guarantee), in pages. |
| − | | + | |- |
| − | The description of each parameter explains the meaning of the <code>barrier</code>
| + | | privvmpages || Memory allocation limit, in pages. |
| − | and the <code>limit</code> and what they should be set to if they are not
| + | |- |
| − | effectively used.
| + | | colspan="2" align="center" | Auxiliary parameters |
| − | | + | |- |
| − | In general, for all parameters the <code>barrier</code> should not be greater than
| + | | lockedpages || Process pages not allowed to be swapped out (pages locked by <code>mlock(2)</code>). |
| − | the <code>limit</code>.</li>
| + | |- |
| − | | + | | shmpages || Total size of shared memory (IPC, shared anonymous mappings and <code>tmpfs</code> objects), in pages. |
| − | <li>The parameters control
| + | |- |
| − | how the resources are distributed between containers in terms of
| + | | physpages || Total number of RAM pages used by processes. |
| − | * limits, i.e. upper boundaries on what this container can consume, and
| + | |- |
| − | * guarantees, i.e. mechanisms ensuring that this container can get the assigned “resources” regardless of the activity and the amount of resources required by other containers.
| + | | numfile || Number of open files. |
| − | | + | |- |
| − | The parameters containing “<code>guar</code>” in their names, | + | | numflock || Number of file locks. |
| − | i.e. <code>vmguarpages</code> and <code>oomguarpages</code> are container's
| + | |- |
| − | guarantees.
| + | | numpty || Number of pseudo-terminals. |
| − | They guarantee availability of resources and certain service level
| + | |- |
| − | up to the value, specified by the <code>barrier</code>,
| + | | numsiginfo || Number of <code>siginfo</code> structures. |
| − | and do not guarantee above the <code>barrier</code>.
| + | |- |
| − | However, these parameters do not impose usage restrictions.
| + | | dcachesize || Total size of <code>dentry</code> and <code>inode</code> structures locked in memory. |
| − | The guarantees are discussed in more detail in the paragraphs describing
| + | |- |
| − | these parameters.
| + | | numiptent || Number of NETFILTER (IP packet filtering) entries. |
| − | | + | |} |
| − | The <code>limit</code> of <code>vmguarpages</code> and <code>oomguarpages</code> should be
| |
| − | set to the maximal value [[LONG_MAX]].
| |
| − | </li>
| |
| − | | |
| − | <li>
| |
| − | For some resource limiting parameters, such as <code>kmemsize</code>,
| |
| − | both <code>barrier</code> and <code>limit</code> settings are effectively used.
| |
| − | If the resource usage exceeds the <code>barrier</code> but doesn't exceed the
| |
| − | <code>limit</code>, vital operations (such as process stack expansion) | |
| − | are still allowed to allocate new
| |
| − | resources, and other ones are not allowed.
| |
| − | A gap between the <code>barrier</code> and the <code>limit</code> gives applications
| |
| − | better chances to handle resource shortage gracefully.
| |
| − | | |
| − | For other resource limiting parameters, such as <code>numproc</code>,
| |
| − | <code>barrier</code> and <code>limit</code> should be set to the same value.
| |
| − | </li>
| |
| − | | |
| − | <li>
| |
| − | Each parameter has “natural units of measurement” — the units
| |
| − | of measurement of values shown via <code>/proc/user_beancounters</code> interface and accepted by [[vzctl]]. | |
| − | Values related to parameters with names starting with <code>num</code> are measured
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| − | in pieces.
| |
| − | Values related to parameters with names ending with <code>pages</code> are measured
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| − | in memory pages (memory page is equal to 4 kilobytes on IA-32 hardware).
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| − | The remaining values (parameters ending with <code>size</code> and <code>buf</code>)
| |
| − | are measured in bytes. See more at [[UBC parameter units]].
| |
| − | </li>
| |
| − | | |
| − | </ol>
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| − | | |
| − | The properties of parameters are summarized in [[UBC parameter properties]].
| |
| − | | |
| − | {{Note|Continue reading with [[UBC primary parameters]], [[UBC secondary parameters]] and [[UBC auxiliary parameters]].}}
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