hendry@simon:~/configs/webconverger$ sudo cat /proc/user_beancounters | grep -v 0$
Version: 2.5
       uid  resource           held    maxheld    barrier      limit    failcnt
      100:  kmemsize         623499    2764532    2752512    2936012         99
            tcprcvbuf             0     496384     319488     524288       4309
            numfile             277       2048       2048       2048        377

sudo vzctl set 100 --privvmpages $((256 * 1024)) --save
sudo vzctl set 100 --vmguarpages $((256 * 256)) --save 
argo$ sudo vzcalc -v 100
Resource     Current(%)  Promised(%)  Max(%)
Low Mem          0.15       1.22       1.22
Total RAM        0.34        n/a        n/a 
Mem + Swap       0.17       0.70        n/a
Alloc. Mem       0.29       6.43      25.42
Num. Proc        0.01        n/a       0.10
--------------------------------------------
Memory           0.34       6.43      25.42

/dev/mem: Permission denied
/usr/share/initramfs-tools/hook-functions: fork: Cannot allocate memory
/usr/sbin/mkinitramfs: fork: Cannot allocate memory

hendry@simon:~$ free -m
             total       used       free     shared    buffers     cached
Mem:          1998       1917         80          0         97       1301
-/+ buffers/cache:        518       1479
Swap:         2047          0       204