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UBC auxiliary parameters

638 bytes added, 05:45, 21 October 2011
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Reverted edits by 109.228.171.118 (talk) to last revision by Kir
important for security and stability of the whole system. Auxiliary
parameters differ much from primary and secondary parameters in this respect.
 
== Introduction ==
The primary functions of auxiliary parameters are the following.
== physpages ==
Total number of RAM pages used by processes in this a container.
For memory pages used by several different containers (mappings of
containers.
For [[VSwap]]-enabled kernels, the <code>barrier</code> should be set to 0,and the <code>limit</code> limits the total size of RAM used by a container. For older kernels, <code>Physpagesphyspages</code> is an accounting-only parameter currently.In future OpenVZ releases, this parameter will allow to provide guaranteedamount of application memory, residing in RAM and not swappable.For compatibility with future versions, the The <code>barrier</code> of thisparameter should be set to <code>0</code> and the <code>limit</code> tothe maximal allowed value 'unlimited' ([[MAX_ULONGLONG_MAX]]).
== numfile ==
of applications in the given container only.
Please visit my       == numiptent ==The number of NETFILTER (IP packet filtering) entries.
The <code>barrier</code> should be set equal to the <code>limit</code>.
There is a restriction on the total number of <code>numiptent</code>.
It depends on the amount of other allocations in so called “vmalloc”
memory area and constitutes about <code>250000</code> entries.
Violation of this restriction may cause failures of operations with
IP packet filter tables (execution of <code>iptables(8)</code>)
in any container or the host system,
or failures of container starts.
RegardsAlso, large <code>numiptent</code> cause considerable slowdown of processingof network packets. It is not recommended to allow containersto create more than 200–300 <code>numiptent</code>.
== swappages ==
of total swap space in a container.
If the <code>limit</code> is set to [[MAX_ULONGLONG_MAX]] (which is the
in-kernel default for this parameter), all the swap space values
parameters (total, used, free) are reported as 0.