It’s often very useful to add customized message (with info or specific commands) on a VM. The easiest way to do that is to use the
/etc/motd file. But what to do if you want to add a message just for one user ?
The first thing that everybody try is to add the message to the
That’s a bad habit:
zapan:~$ ssh me@zapan 'uptime'
You shouldn't see this message !
17:16:45 up 4 days, 7:29, 4 users, load average: 1.81, 1.25, 0.83
As you can see the content is displayed in case of a non-interactive non-login shell invoked via ssh. Instead add your message to the
Further Reading and sources
List containers sorted by CPU usage:
# vzlist -o ctid,name,laverage
List containers sorted by TCP sender buffer usage:
# vzlist -H -o ctid,name,tcpsndbuf | sort -r -n -k3
List containers sorted by TCP receive buffer usage:
# vzlist -H -o ctid,name,tcprcvbuf | sort -r -n -k3
List containers sorted by overall resources consumption:
for i in `vzlist -H -o veid`;do echo $i; vzcalc $i; echo "========"; done;
Add a new network interface to a container:
# vzctl set <id> --netif_add eth0 --save
PostgreSQL is great, but the manner its work is sometime… a little unsettling. For example, Postgres like spawning a lots of little processes that communicate by IPC, which means using chunk of shared memory. Sometime you can hit the
To obtain the current value :
You can ovverride the default value into the
Add a line like this for example:
kernel.shmmax = 43554432
And don’t forget to make a
sysctl -p and restart postgres to take into account the new value.