HN # lsmod | grep ppp

ppp_deflate             9793  2
zlib_deflate           21977  1 ppp_deflate
ppp_async              15169  1
crc_ccitt               6337  1 ppp_async
ppp_generic            30165  6 ppp_deflate,ppp_async
slhc                   10561  1 ppp_generic

HN # vzctl set [VEID]--devices c:108:0:rw --save
HN # vzctl set [VEID] --features ppp:on --save
HN # vzctl exec [VEID] mknod /dev/ppp c 108 0
HN # vzctl exec [VEID] chmod 600 /dev/ppp

VPS:

apt-get install ppp pptpd

<1>

If your default LANG environment variable was set to something like en_US.UTF-8, you can reduce shell (bash) startup time up to ~15% with LANG=C.

<2>

a single VCPU to each container. => significantly reduce overhead on SMP memory coherence

<3>

ethtool -k venet0

# ethtool -K venet0 tx on sg on

yum offers to delete the second-oldest version

try to use yum update when you want to save your previous kernel.
yum install kernel, will always delete oldest one.

vzctl --verbose stop 2001

strace -f -o strace.out vzctl stop 2001

vzctl stop <VEID> --fast

#

execute halt, it just try to kill VE's init.