Changing Container Resource Parameters

The Configure page allows you to change the disk, CPU, and system resources the Container may allocate.

The CPU-related resource management is based on the following parameters:

Parameter	Description
`cpuunits`	This is a positive integer number that determines the minimal guaranteed share of the CPU time your Container will receive.
`cpulimit`	This is a positive number indicating the CPU time in percent the corresponding Container is not allowed to exceed.
`burst_cpulimit`	The CPU power limit, in percent, the Container cannot exceed. The limitations set in this parameter are applied to the Container when it exceeds the limit specified in the `burst_cpu_avg_usage` parameter.
`burst_cpu_avg_usage`	The CPU usage limit, in percent, set for the Container. This limit is calculated as the ratio of the current Container CPU usage to the CPU limit (i.e to the value of the `CPULIMIT` parameter) set for the Container. If the limit is not specified, the full CPU power of the Hardware Node is considered as the CPU limit. Upon exceeding the `burst_cpu_avg_usage` limit, the `burst_cpulimit` limit is applied to the Container.
`cpuguarantee`	This is a positive integer number indicating the CPU time, in percent, the corresponding Container is guaranteed to receive. If both the `cpuguarantee` and `cpuunits` parameters are set, the `cpuguarantee` parameter is first taken into account when distributing processor(s) time among the Containers existing on the Node; the remaining CPU time, if any, is given to the Containers in accordance with the value of the `cpuunits` parameter.
`cpus`	The number of CPUs set to handle all the processes inside the given Container. By default, any Container is allowed to consume the CPU time of all processors on the Node.

The disk-related resource management is based on the following parameters:

Parameter	Description
`diskspace`	Total size of disk space consumed by the Container. When the space used by the Container hits the soft limit, the Container can allocate additional disk space up to the hard limit during the grace period indicated by the `quotatime` parameter value.
`diskinodes`	Total number of disk inodes (files, directories, and symbolic links) allocated by the Container. When the number of inodes used by the Container hits the soft limit, the Container can create additional inodes up to the hard limit during the grace period indicated by the `quotatime` parameter value.
`quotaugidlimit`	Number of user/group IDs allowed for the Container internal disk quota. If set to 0, UID/GID quota will not be enabled.
`quotatime`	The grace period for the disk quota overusage defined in seconds. The Container is allowed to temporarily exceed its quota soft limits for no more than the `QUOTATIME` period.
`ioprio`	The Container priority for disk I/O operations. The allowed range of values is 0-7. The greater the priority, the more time the Container has for writing to and reading from the disk. The default Container priority is 4.

The memory-related resource management parameters are divided into 4 groups: memory parameters, primary system parameters, secondary system parameters, and auxiliary system parameters.

Windows-based Containers use only the primary system parameters.

For Linux-based Containers, this screen displays the memory-based, or the system-based, or both memory- and system-based Container resources data, depending on your memory management configuration:

If the memory management mode is enabled for the Container, it can be allocated memory in much the same way as a certain amount of physical memory is installed on a physical computer. This is the recommended mode for managing Containers for most administrators.
If the system management mode is enabled, the Container's performance depends on the values of quite a number of fine-grained parameters. The primary parameters are the starting point for defining the relative power of a Container. The secondary parameters are dependent on the primary ones and are calculated from them according to a set of constraints. The auxiliary parameters help improve fault isolation among applications in a Container and the way applications handle errors and consume resources.
If both resource management modes are used, the more restrictive value is taken into account each time the system makes the decision whether to allocate this or that resource to the Container.

Memory parameters

Parameter	Description
`slmmemorylimit`	An approximation of the size of the physical memory allocated to the Container. In other words, the Container performance is similar to the performance of a physical computer with as much physical memory installed as is indicated in this parameter.

Primary system parameters

Parameter	Description
`numproc`	The maximal number of processes the Container may create.
`numsessions`	The number of simultaneous terminal sessions that can be opened to the Container.
`vprvmem`	The size of private (or potentially private) memory allocated by the Container. The memory that is always shared among different applications is not included in this resource parameter.
`numtcpsock`	The number of TCP sockets (PF_INET family, SOCK_STREAM type). This parameter limits the number of TCP connections and, thus, the number of clients the server application can handle in parallel.
`numothersock`	The number of sockets other than TCP ones. Local (UNIX-domain) sockets are used for communications inside the system. UDP sockets are used, for example, for Domain Name Service (DNS) queries. UDP and other sockets may also be used in some very specialized applications (SNMP agents and others).
`vmguarpages`	The memory allocation guarantee, in pages. Container applications are guaranteed to be able to allocate additional memory so long as the amount of memory accounted as privvmpages (see the auxiliary parameters) does not exceed the configured barrier of the vmguarpages parameter. Above the barrier, additional memory allocation is not guaranteed and may fail in case of overall memory shortage.
`avnumproc`	The average number of processes and threads.

Secondary system parameters

Parameter	Description
`kmemsize`	The size of unswappable kernel memory allocated for the internal kernel structures for the processes of a particular Container. Note: For the Virtuozzo Containers 64-bit version for IA-64 processors, it takes 4 (four) times more the size of the kernel memory than that for the Virtuozzo Containers 32-bit version to handle one and the same process.
`tcpsndbuf`	The total size of send buffers for TCP sockets, i.e. the amount of kernel memory allocated for the data sent from an application to a TCP socket, but not acknowledged by the remote side yet.
`tcprcvbuf`	The total size of receive buffers for TCP sockets, i.e. the amount of kernel memory allocated for the data received from the remote side, but not read by the local application yet.
`othersockbuf`	The total size of UNIX-domain socket buffers, UDP, and other datagram protocol send buffers.
`dgramrcvbuf`	The total size of receive buffers of UDP and other datagram protocols.
`oomguarpages`	The out-of-memory guarantee, in pages. Any Container process will not be killed even in case of heavy memory shortage if the current memory consumption (including both physical memory and swap) does not reach the oomguarpages barrier.
`privvmpages`	The size of private (or potentially private) memory allocated by an application. The memory that is always shared among different applications is not included in this resource parameter.

Auxiliary system parameters

Parameter	Description
`lockedpages`	The memory not allowed to be swapped out (locked with the `mlock()` system call), in pages.
`shmpages`	The total size of shared memory (including IPC, shared anonymous mappings and tmpfs objects) allocated by the processes of a particular Container, in pages.
`numfile`	The number of files opened by all Container processes.
`numflock`	The number of file locks created by all Container processes.
`numpty`	The number of pseudo-terminals, such as an ssh session, screen or xterm applications, etc.
`numsiginfo`	The number of siginfo structures (essentially, this parameter limits the size of the signal delivery queue).
`dcachesize`	The total size of dentry and inode structures locked in the memory.
`numiptent`	The number of IP packet filtering entries.

Notes: The parameters containing "pages" in their names are measured in 4096-byte pages in the Virtuozzo Containers 32-bit version and in 16384-byte pages in the Virtuozzo Containers 64-bit version for IA-64 processors.

In the Virtuozzo Containers 64-bit versions, all the system parameter values are 64-bit and, therefore, can exceed the values in the Virtuozzo Containers 32-bit version (where the parameters values are 32-bit). For example, the limit of the oomguarpages parameter in the Virtuozzo Containers 64-bit version for IA-64 processors can be maximally set to 9223372036854775807 instead of 2147483647 in the Virtuozzo Containers 32-bit version. To learn more about the difference between the Virtuozzo Containers 64-bit and 32-bit versions turn to the Virtuozzo Containers for 64-bit Processors section of the Parallels Virtuozzo Containers User's Guide.

The information on the available parameters is presented in the table with the following columns:

Column Name	Description
Parameter	The name of the resource parameter.
Current Usage	Indicates the consumption of the corresponding resource by the Container at the moment of calling the current Infrastructure Manager page. The units in which the consumption is measured are specified in the Units column. If the current usage is not available (n/a), it means that either the Container is not running, or the nature of the resource does not suggest its changing over time.
Limit	The limit on the consumption of the given resource by the Container. The units in which the limit is measured are specified in the Units column.
Soft Limit	The limit on the consumption of the given resource by the Container that can be exceeded only if the system is not fully loaded. The units in which the limit is measured are specified in the Units column.
Hard Limit	The limit on the consumption of the given resource by the current Container that cannot be exceeded under any circumstances. The units in which the limit is measured are specified in the Units column.
Limited	If this checkbox is cleared, the limits on the corresponding resource are not set for the Container.
Units	The units in which the resource values are measured.
Description	The description of the resource parameter.

You can use the Validate button at the foot of the page to display if any constraint violations have been found and learn the corresponding constraints on the resource management parameters.

If you have entered new values for one or several resource parameters and then decided to change them to the default values from the Container sample, you can reset the new values by clicking the curved arrow against the corresponding parameter(s).

After you have customized the Container parameters and checked their interdependencies, click Submit.

To customize the resources of several Containers at once, use one of the Parallels Infrastructure Manager group change wizards.

You can also edit the Container resource values via ssh by using the vzctl utility. Mind though that you need to use the --save option to have the edited UBC parameters reported by Parallels Infrastructure Manager or Parallels Power Panel. For more information, see Virtuozzo Reference Guide: Virtuozzo Command Line Interface > vzctl > vzctl set.

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