Difference between revisions of "Migration from Linux-VServer to OpenVZ"

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("fixed" openvz installation description -- refer to quick install)
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{{Roughstub}}
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Current document describes the migration from Linux-VServer based virtualization solution to OpenVZ.
 
Current document describes the migration from Linux-VServer based virtualization solution to OpenVZ.
  
Line 90: Line 92:
 
2. Starting migration to OpenVZ: downloading and installing the stable OpenVZ kernel.
 
2. Starting migration to OpenVZ: downloading and installing the stable OpenVZ kernel.
  
First of all we should download and install the latest stable version of OpenVZ kernel:
+
Install the OpenVZ kernel, as described in [[quick installation]].  
 
 
<code>
 
  #  wget http://openvz.org/download/kernel/stable/ovzkernel-2.6.9-023stab032.1.i686.rpm
 
  #  rpm -ihv ovzkernel-2.6.9-023stab032.1.i686.rpm
 
</code>
 
 
 
If you use grub bootloader, then before installing the OpenVZ kernel file /boot/grub/grub.conf looked like this:
 
 
 
<code>
 
  # grub.conf generated by anaconda
 
  #
 
  # Note that you do not have to rerun grub after making changes to this file
 
  # NOTICE:  You have a /boot partition.  This means that
 
  #          all kernel and initrd paths are relative to /boot/, eg.
 
  #          root (hd0,0)
 
  #          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
 
  #          initrd /initrd-version.img
 
  #boot=/dev/sda
 
  default=0
 
  timeout=5
 
  splashimage=(hd0,0)/grub/splash.xpm.gz
 
  hiddenmenu
 
  title Red Hat Enterprise Linux AS (2.6.17.13-vs2.0.2.1)
 
          root (hd0,0)
 
          kernel /vmlinuz-2.6.17.13-vs2.0.2.1 ro root=/dev/VolGroup00/LogVol00
 
          initrd /initrd-2.6.17.13-vs2.0.2.1.img
 
</code>
 
 
 
After installing it should look like this:
 
 
 
<code>
 
  # grub.conf generated by anaconda
 
  #
 
  # Note that you do not have to rerun grub after making changes to this file
 
  # NOTICE:  You have a /boot partition.  This means that
 
  #          all kernel and initrd paths are relative to /boot/, eg.
 
  #          root (hd0,0)
 
  #          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
 
  #          initrd /initrd-version.img
 
  #boot=/dev/sda
 
  default=0
 
  timeout=5
 
  splashimage=(hd0,0)/grub/splash.xpm.gz
 
  hiddenmenu
 
  title Red Hat Enterprise Linux AS (2.6.9-023stab032.1)
 
          root (hd0,0)
 
          kernel /vmlinuz-2.6.9-023stab032.1 ro root=/dev/VolGroup00/LogVol00
 
          initrd /initrd-2.6.9-023stab032.1.img
 
  title Red Hat Enterprise Linux AS (2.6.17.13-vs2.0.2.1)
 
          root (hd0,0)
 
          kernel /vmlinuz-2.6.17.13-vs2.0.2.1 ro root=/dev/VolGroup00/LogVol00
 
          initrd /initrd-2.6.17.13-vs2.0.2.1.img
 
</code>
 
 
 
And the default parameter should be set to 0 in purpose to make the OpenVZ kernel work by default after rebooting the machine.
 
  
Some more manual configuring needed on this step:
+
After the kernel is installed, reboot the machine. After rebooting and logging in you will see the following reply on vserver-stat call:
Update the /etc/sysctl.conf file according to the following listing ( Comment all other settings that are not presented
 
in listing below ):
 
 
 
<code>
 
  # On Hardware Node we generally need
 
  # packet forwarding enabled and proxy arp disabled
 
  net.ipv4.ip_forward = 1
 
  net.ipv4.conf.default.proxy_arp = 0
 
  # Enables source route verification
 
  net.ipv4.conf.all.rp_filter = 1
 
  # Enables the magic-sysrq key
 
  kernel.sysrq = 1
 
  # TCP Explict Congestion Notification
 
  #net.ipv4.tcp_ecn = 0
 
  # we do not want all our interfaces to send redirects
 
  net.ipv4.conf.default.send_redirects = 1
 
  net.ipv4.conf.all.send_redirects = 0
 
</code>
 
 
 
As the SELinux should be disabled, put the following line to /etc/sysconfig/selinux:
 
 
 
<code>
 
  SELINUX=disabled
 
</code>
 
 
 
Now reboot the machine. After rebooting and loggin in you will see the following reply on vserver-stat call:
 
  
 
<code>
 
<code>
Line 181: Line 102:
 
</code>
 
</code>
  
It is a natural thing that now virtual environments v345 is unavailable. The following steps will be devoted to making them
+
It is a natural thing that now virtual environment v345 is unavailable. The following steps will be devoted to making it
 
work over OpenVZ kernel.
 
work over OpenVZ kernel.
  
3. Downloading and istalling vzctl package
+
3. Downloading and installing vzctl package
 
 
OpenVZ solution reqires installing a set of tools: vzctl and vzquota packages. Let us download and install this tools:
 
  
<code>
+
OpenVZ solution requires installing a set of tools: vzctl and vzquota packages. Download and install it, as described in [[quick installation]].
  # wget http://openvz.org/download/utils/vzctl-3.0.13-1.i386.rpm
 
  # wget http://openvz.org/download/utils/vzquota-3.0.9-1.i386.rpm
 
  # rpm -Uhv vzctl-3.0.13-1.i386.rpm vzquota-3.0.9-1.i386.rpm
 
</code>
 
  
 
If rpm complains about unresolved dependencies, you'll have to satisfy them first, then repeat the installation.
 
If rpm complains about unresolved dependencies, you'll have to satisfy them first, then repeat the installation.
Line 205: Line 120:
 
</code>
 
</code>
  
Currently vzlist util is unable to find any container:
+
Currently vzlist utility is unable to find any containers:
  
 
<code>
 
<code>
Line 215: Line 130:
 
4. Updating different configurations in purpose to make existing templates work
 
4. Updating different configurations in purpose to make existing templates work
  
Move the existing templates of guest OSes to the right place:
+
Move the existing templates of guest OSs to the right place:
  
 
<code>
 
<code>
Line 257: Line 172:
 
</code>
 
</code>
  
5. Testing how the guest OSes succesfully work over OpenVZ. Reference to Users Guide of OpenVZ (vzctl).
+
5. Testing how the guest OSs successfully work over OpenVZ. Reference to Users Guide of OpenVZ (vzctl).
  
 
After rebooting you will be able to see running container 345 that have been
 
After rebooting you will be able to see running container 345 that have been

Revision as of 13:46, 11 March 2008

Current document describes the migration from Linux-VServer based virtualization solution to OpenVZ.

Description of challenge:

The challenge is migration from Linux-Vserver to OpenVZ by booting the OpenVZ kernel and updating the existing configs of utility level in purpose to make the existing guest OSes work over OpenVZ kernel.

Details of migration process. Step by step:

1. Initial conditions: the following example of Linux-VServer based solution was used for the experiment:

- Kernel linux-2.6.17.13 was patched by the patch-2.6.17.13-vs2.0.2.1.diff and rebuild; - Util-vserver-0.30.211 tools were used for creating containers;

 # vserver-info
 Versions:
 Kernel: 2.6.17.13-vs2.0.2.1
 VS-API: 0x00020002
 util-vserver: 0.30.211; Dec  5 2006, 17:10:21
 Features:
 CC: gcc, gcc (GCC) 3.4.3 20041212 (Red Hat 3.4.3-9.EL4)
 CXX: g++, g++ (GCC) 3.4.3 20041212 (Red Hat 3.4.3-9.EL4)
 CPPFLAGS: 
 CFLAGS: '-g -O2 -std=c99 -Wall -pedantic -W -funit-at-a-time'
 CXXFLAGS: '-g -O2 -ansi -Wall -pedantic -W -fmessage-length=0 -funit-at-a-time'
 build/host: i686-pc-linux-gnu/i686-pc-linux-gnu
 Use dietlibc: yes
 Build C++ programs: yes
 Build C99 programs: yes
 Available APIs: v13,net
 ext2fs Source: kernel
 syscall(2) invocation: alternative
 vserver(2) syscall#: 273/glibc
 Paths:
 prefix: /usr/local
 sysconf-Directory: ${prefix}/etc
 cfg-Directory: ${prefix}/etc/vservers
 initrd-Directory: $(sysconfdir)/init.d
 pkgstate-Directory: ${prefix}/var/run/vservers
 vserver-Rootdir: /vservers
 #

VServer v345 was built using vserver vX build utility and populated by using the tarballed template of Fedora Core 4.

 # vserver v345 start
 Starting system logger:                                    [  OK  ]
 Initializing random number generator:                      [  OK  ]
 Starting crond: l:                                         [  OK  ]
 Starting atd:                                              [  OK  ]
 # vserver v345 enter
 [/]# ls -l
 total 44
 drwxr-xr-x    2 root     root         4096 Oct 26  2004 bin
 drwxr-xr-x    3 root     root         4096 Dec  8 17:16 dev
 drwxr-xr-x   27 root     root         4096 Dec  8 15:21 etc
 -rw-r--r--    1 root     root            0 Dec  8 15:33 halt
 drwxr-xr-x    2 root     root         4096 Jan 24  2003 home
 drwxr-xr-x    7 root     root         4096 Oct 26  2004 lib
 drwxr-xr-x    2 root     root         4096 Jan 24  2003 mnt
 drwxr-xr-x    3 root     root         4096 Oct 26  2004 opt
 -rw-r--r--    1 root     root            0 Dec  7 20:17 poweroff
 dr-xr-xr-x   80 root     root            0 Dec  8 11:38 proc
 drwxr-x---    2 root     root         4096 Dec  7 20:17 root
 drwxr-xr-x    2 root     root         4096 Oct 26  2004 sbin
 drwxrwxrwt    2 root     root           40 Dec  8 17:16 tmp
 drwxr-xr-x   15 root     root         4096 Jul 27  2004 usr
 drwxr-xr-x   17 root     root         4096 Oct 26  2004 var
 [/]# sh
 sh-2.05b#
 .........

As a result we obtain running virtual environment v345:

 # vserver-stat
 CTX   PROC    VSZ    RSS  userTIME   sysTIME    UPTIME NAME
 0       51  90.9M  26.3M   0m58s75   2m42s57  33m45s93 root server
 49153    4  10.2M   2.8M   0m00s00   0m00s11  21m45s42 v345
 # 

2. Starting migration to OpenVZ: downloading and installing the stable OpenVZ kernel.

Install the OpenVZ kernel, as described in quick installation.

After the kernel is installed, reboot the machine. After rebooting and logging in you will see the following reply on vserver-stat call:

 # vserver-stat
 can not change context: migrate kernel feature missing and 'compat' API disabled: Function not implemented
 #

It is a natural thing that now virtual environment v345 is unavailable. The following steps will be devoted to making it work over OpenVZ kernel.

3. Downloading and installing vzctl package

OpenVZ solution requires installing a set of tools: vzctl and vzquota packages. Download and install it, as described in quick installation.

If rpm complains about unresolved dependencies, you'll have to satisfy them first, then repeat the installation. Then launch the OpenVZ:

 # /sbin/service vz start
 Starting OpenVZ:                                           [  OK  ]
 Bringing up interface venet0:                              [  OK  ]
 Configuring interface venet0:                              [  OK  ]
 #

Currently vzlist utility is unable to find any containers:

 # vzlist
 Containers not found
 #

4. Updating different configurations in purpose to make existing templates work

Move the existing templates of guest OSs to the right place:

 # cd /vz
 # mkdir private
 # mkdir 345
 # mv /vservers/v345 /vz/private/345

Now it is time for creating configuration files for OpenVZ container. Use the basic sample configuration presented in /etc/sysconfig/vz-scripts/ve-vps.basic.conf-sample file:

 # cd /etc/sysconfig/vz-scripts
 # cp ve-vps.basic.conf-sample 345.conf

Update the ON_BOOT string in 345.conf file by typing:

 .....
 ONBOOT="yes"
 .....

to make it boot on node restart, and add a couple of strings related to the particular container 345:

 .....
 VE_ROOT="/vz/root/345"
 VE_PRIVATE="/vz/private/345"
 ORIGIN_SAMPLE="vps.basic"
 HOSTNAME="test345.my.org"
 IP_ADDRESS="192.168.0.145"
 .....

And reboot the machine:

 # reboot

5. Testing how the guest OSs successfully work over OpenVZ. Reference to Users Guide of OpenVZ (vzctl).

After rebooting you will be able to see running container 345 that have been migrated from vserver:

 # vzlist -a
 CTID      NPROC  STATUS  IP_ADDR         HOSTNAME
 345          5   running 192.168.0.145   test345.my.org
 #

And run commands on it:

 # vzctl exec 345 ls -l
 total 48
 drwxr-xr-x    2 root     root         4096 Oct 26  2004 bin
 drwxr-xr-x    3 root     root         4096 Dec 11 12:42 dev
 drwxr-xr-x   27 root     root         4096 Dec 11 12:44 etc
 -rw-r--r--    1 root     root            0 Dec 11 12:13 fastboot
 -rw-r--r--    1 root     root            0 Dec  8 15:33 halt
 drwxr-xr-x    2 root     root         4096 Jan 24  2003 home
 drwxr-xr-x    7 root     root         4096 Oct 26  2004 lib
 drwxr-xr-x    2 root     root         4096 Jan 24  2003 mnt
 drwxr-xr-x    3 root     root         4096 Oct 26  2004 opt
 -rw-r--r--    1 root     root            0 Dec  7 20:17 poweroff
 dr-xr-xr-x   70 root     root            0 Dec 11 12:42 proc
 drwxr-x---    2 root     root         4096 Dec  7 20:17 root
 drwxr-xr-x    2 root     root         4096 Dec 11 12:13 sbin
 drwxrwxrwt    2 root     root         4096 Dec  8 12:40 tmp
 drwxr-xr-x   15 root     root         4096 Jul 27  2004 usr
 drwxr-xr-x   17 root     root         4096 Oct 26  2004 var
 #

Potential issues: This work has in progress status. Some issues may take place with tuning the network for containers. To be continued.