UBC

UBC, or User Beancounters — is a set of limits and guarantees contolled per VE. You can see the current usage values and limits by examining the output of /proc/user_beancounters file.

Here is the example of /proc/user_beancounters inside VE with ID of 123:

# cat /proc/user_beancounters
Version: 2.5
       uid  resource           held    maxheld    barrier      limit    failcnt
       123: kmemsize         836919    1005343    2752512    2936012          0
            lockedpages           0          0         32         32          0
            privvmpages        4587       7289      49152      53575          0
            shmpages             39         39       8192       8192          0
            dummy                 0          0          0          0          0
            numproc              20         26         65         65          0
            physpages          2267       2399          0 2147483647          0
            vmguarpages           0          0       6144 2147483647          0
            oomguarpages       2267       2399       6144 2147483647          0
            numtcpsock            3          3         80         80          0
            numflock              3          4        100        110          0
            numpty                1          1         16         16          0
            numsiginfo            0          1        256        256          0
            tcpsndbuf             0          0     319488     524288          0
            tcprcvbuf             0          0     319488     524288          0
            othersockbuf       6684       7888     132096     336896          0
            dgramrcvbuf           0       8372     132096     132096          0
            numothersock          8         10         80         80          0
            dcachesize        87672      92168    1048576    1097728          0
            numfile             238        306       2048       2048          0
            dummy                 0          0          0          0          0
            dummy                 0          0          0          0          0
            dummy                 0          0          0          0          0
            numiptent            10         16        128        128          0

See more at setting UBC parameters and Resource shortage.