Installing And Using OpenVZ On Fedora 15 - Page 2
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2 Using OpenVZ
Before we can create virtual machines with OpenVZ, we need to have a template for the distribution that we want to use in the virtual machines in the /vz/template/cache directory. The virtual machines will be created from that template. You can find a list of precreated templates on http://wiki.openvz.org/Download/template/precreated.
I want to use Fedora 15 in my virtual machines, so I download a Fedora 15 template:
cd /vz/template/cache
wget http://download.openvz.org/template/precreated/beta/fedora-15-x86.tar.gz
I will now show you the basic commands for using OpenVZ.
To set up a VPS from the Fedora 15 template, run:
vzctl create 101 --ostemplate fedora-15-x86 --config basic
The 101 must be a uniqe ID - each virtual machine must have its own unique ID. You can use the last part of the virtual machine's IP address for it. For example, if the virtual machine's IP address is 192.168.0.101, you use 101 as the ID.
If you want to have the vm started at boot, run
vzctl set 101 --onboot yes --save
To set a hostname and IP address for the vm, run:
vzctl set 101 --hostname test.example.com --save
vzctl set 101 --ipadd 192.168.0.101 --save
Next we set the number of sockets to 120 and assign a few nameservers to the vm:
vzctl set 101 --numothersock 120 --save
vzctl set 101 --nameserver 8.8.8.8 --nameserver 8.8.4.4 --nameserver 145.253.2.75 --save
(Instead of using the vzctl set commands, you can as well directly edit the vm's configuration file which is stored in the /etc/vz/conf/ directory. If the ID of the vm is 101, then the configuration file is /etc/vz/conf/101.conf.)
To start the vm, run
vzctl start 101
To set a root password for the vm, execute
vzctl exec 101 passwd
You can now either connect to the vm via SSH (e.g. with PuTTY), or you enter it as follows:
vzctl enter 101
To leave the vm's console, type
exit
To stop a vm, run
vzctl stop 101
To restart a vm, run
vzctl restart 101
To delete a vm from the hard drive (it must be stopped before you can do this), run
vzctl destroy 101
To get a list of your vms and their statuses, run
vzlist -a
[root@server1 ~]# vzlist -a
CTID NPROC STATUS IP_ADDR HOSTNAME
101 12 running 192.168.0.101 test.example.com
[root@server1 ~]#
To find out about the resources allocated to a vm, run
vzctl exec 101 cat /proc/user_beancounters
[root@server1 ~]# vzctl exec 101 cat /proc/user_beancounters
Version: 2.5
uid resource held maxheld barrier limit failcnt
101: kmemsize 608099 853271 11055923 11377049 0
lockedpages 0 0 256 256 0
privvmpages 9982 10340 65536 69632 0
shmpages 641 657 21504 21504 0
dummy 0 0 0 0 0
numproc 10 13 240 240 0
physpages 1334 1489 0 2147483647 0
vmguarpages 0 0 33792 2147483647 0
oomguarpages 1334 1489 26112 2147483647 0
numtcpsock 3 3 360 360 0
numflock 0 1 188 206 0
numpty 1 2 16 16 0
numsiginfo 0 2 256 256 0
tcpsndbuf 26832 0 1720320 2703360 0
tcprcvbuf 49152 0 1720320 2703360 0
othersockbuf 8944 26216 1126080 2097152 0
dgramrcvbuf 0 8380 262144 262144 0
numothersock 6 11 120 120 0
dcachesize 0 0 3409920 3624960 0
numfile 233 280 9312 9312 0
dummy 0 0 0 0 0
dummy 0 0 0 0 0
dummy 0 0 0 0 0
numiptent 10 10 128 128 0
[root@server1 ~]#
The failcnt column is very important, it should contain only zeros; if it doesn't, this means that the vm needs more resources than are currently allocated to the vm. Open the vm's configuration file in /etc/vz/conf/ and raise the appropriate resource, then restart the vm.
To find out more about the vzctl command, run
man vzctl
3 Links
- OpenVZ: http://openvz.org/
- Fedora: http://fedoraproject.org/
