Converting Shared VPSes into Hardware Nodes

Original Publishing Date:
2022-04-13

This KB article contains the detailed instructions of how to convert Shared VPSes into Hardware Nodes on OA, in addition to the ones available in OA guide .

Please note that Virtuozzo version must be at least 4.7

Important(!) - Do not perform a conversion on earlier VZ versions

Preparations part

Passwordless (key-based) access must be configured from OA Management Node to all VZ nodes where shared containers are located. The following resource may be useful - SSH login without password
Configure Front Net and the Back Net virtual networks on VZ node:

a) check networks - # vznetcfg net list

b) create new networks if needed - # vznetcfg net new BackNet , # vznetcfg net new FrontNet

c) check IP addresses and how they are bound to networks - # ip a l or # ifconfig -a

d) associate new network with one of them according to the following example: # vznetcfg net addif BackNet eth1

Finally virtual networks configuration on VZ node will be similar to the following example:
```
[root@VZnode ~]# vznetcfg net list

Network ID        Status      Master Interface  Slave Interfaces
BackNet           active      eth1
FrontNet          active      eth0
```
Check the values of the following parametres:

a) --host-id - VPSes ID in OA , may be found in OA CP at: Services > Cloud Infrastructure > VPSs

b) --hw-host-id - ID of the VPS Hardware Node (VZ node), may be found at: Services > Cloud Infrastructure > VPS Hardware Nodes

c) --gateway - Gateway IP address, may be checked on VZ node by running the following command: # netstat -nr

Example:
```
# netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
...
...
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 eth1
0.0.0.0         10.39.1.1       0.0.0.0         UG        0 0          0 eth0
```
See the last line in the output - in this example, Gateway IP is 10.39.1.1

*Note that for VPSes that have Internal IP only assigned, Gateway value may be checked by running # netstat -nr inside of the container. Often in such cases Gateway IP is 169.254.0.0

d) --backnet - name of the virtual Back Net configured for the container.

e) --frontnet - name of the virtual Back Net configured for the container.
Create a backup copy of the containers' configs:
```
# cp -p /etc/sysconfig/vz-scripts/<CTID>.conf /etc/sysconfig/vz-scripts/<CTID>.conf.bak 
```
If the conversion fails for some reason, it is possible to restore container's network settings by replacing it's config with backup and CT restart.

Alternatively, you may create a full container's backup (clone) using the following command and set --onboot no parameter for the clone (so the cloned CT will not be started automatically after VZ node reboot):
```
    # vzmlocal -C <source_CTID>:<copy_CTID>
    # vzctl set <copy_CTID> --save --onboot no
```
The copy_CTID must be free, i.e. not assigned to any other container.

Note that cloning of large containers may take a significant amount of time.

Conversion

Once password-less access from MN to VZ node and and virtual networks are configued and host-id, hw-host-id and gateway values are clarified for a specific VPS, conversion script may be launched on MN according to the following example:

For VPS with both External and Internal IPs assigned:

/usr/local/pem/bin/convert_vps_to_host.py --host-id 32 --hw-host-id 2 --gateway 10.39.1.1 --backnet BackNet --frontnet FrontNet --verbose

For VPS with Internal IP only:

/usr/local/pem/bin/convert_vps_to_host.py --host-id 32 --hw-host-id 2 --gateway 169.254.0.0 --backnet BackNet --verbose

Note that the 'host id' values and IP addresses in the above commands are examples only and must be replaced with the real values

Known issues:

128008 Communication failure with remote server
128612 missing networks on venet0
128010 network interfaces are missing on Shared VPS
126740 ValueError: invalid literal for int(): auto
124085 There is no networks on host`
128151 convert_vps_to_host.py uses ServiceCT IP while SSHing to VPS HW node
128153 RTNETLINK answers: No such process
127179 Shared VPS located on hardware host %d but passed %s'
128609 Host pemhost123 is not a Shared VPS
128096 There is no password, pubkey ssh access to host
127178 Network is missing on host
128608 Failed to find %s backnet IP
128613 ERROR poaupdater.uUtil.ExecFailed
128611 There is no YUM tool installed on host