User Beancounters

[eUK-Scott]

User Beancounters is a set of limits and guarantees controlled per Virtual Environment. UBC is the major component of OpenVZ resource management.

Primary parameters

• numproc - Number of processes and threads.
• numtcpsock - Number of TCP sockets.
• numothersock - Number of sockets other than TCP.
• vmguarpages - Memory allocation guarantee, in pages.

Secondary parameters

• kmemsize - Size of unswappable kernel memory, allocated for processes in this VE.
• tcpsndbuf - Total size of TCP send buffers.
• tcprcvbuf - Total size of TCP receive buffers.
• othersockbuf - Total size of UNIX-domain socket buffers, UDP and other datagram protocol send buffers.
• dgramrcvbuf - Receive buffers of UDP and other datagram protocols.
• oomguarpages - The guaranteed amount of memory for the case the memory is “over-bookedâ€� (out-of-memory kill guarantee), in pages.
• privvmpages - Memory allocation limit, in pages.

Auxiliary parameters

• lockedpages - Process pages not allowed to be swapped out (pages locked by mlock(2)).
• shmpages - Total size of shared memory (IPC, shared anonymous mappings and tmpfs objects), in pages.
• physpages - Total number of RAM pages used by processes.
• numfile - Number of open files.
• numflock - Number of file locks.
• numpty - Number of pseudo-terminals.
• numsiginfo - Number of siginfo structures.
• dcachesize - Total size of dentry and inode structures locked in memory.
• numiptent - Number of NETFILTER (IP packet filtering) entries.

UBC parameter units

1. entries which name has word 'page' are measured in memory pages (4K on x86 and x86_64, 16K for IA64). These are privvmpages, oomguarpages and others.
   
2. entries with names like 'num*' are measured in items. i.e. numproc - number of processes, numiptent - number of iptables entries.
   
3. other entries like kmemsize, tcprcvbuf/tcpsndbuf are measured in bytes

The proc filesystem entry showing resource control information is /proc/user_beancounters file.