Parallels Virtualization and Automation Software

RESOLUTION

UBC parameters (or User Beancounters, or QoS (Quality of Service) parameters) is a set of limits and guarantees controlled per VE. UBC is the major component of Virtuozzo resource management.

The proc filesystem entry showing resource control information is /proc/user_beancounters file inside a VE. /proc/user_beancounters on a hardware node contains UBC parameters for all VEs running on a node.

An example content of /proc/user_beancounters is shown below:

The field uid is a numeric identifier of the VE.

For accountable parameters, the field held shows the current counter for the VE (resource “usage”), and the field maxheld shows the counter's maximum for the last accounting period. The accounting period is usually the lifetime of the VE.

The field failcnt shows the number of refused “resource allocations” for the whole lifetime of the process group.

The barrier and limit fields are resource control settings. For some parameters, only one of them may be used, for some parameters — both. These fields may specify limits or guarantees, and the exact meaning of them is parameter-specific.

Description of each UBC parameter contains information about the difference between the barrierlimit for the parameter and can be found in Virtuozzo Management of System Resources Administrator's Guide which is shipped with Virtuozzo (docs/VzLinuxSLM.pdf file).