9. Virtual private servers (VPS)

Create a VPS

In order to provide a simple and quick way to create a new virtual server instance, SERVERware offers virtual server templates. A template is a base virtual server defined with a unique configuration and settings. A virtual server based on a particular template acquires the configurations and settings of the template. 

Thus, templates are used to conveniently and efficiently create a set of identical virtual servers. By default, virtual servers created from templates use dynamic provisioning. 

In the context of templates, dynamic provisioning means that all virtual machines based on a given template share the same base image as the template.

There are three types of templates in SERVERware:

1. SERVICE
2. SYSTEM
3. OCI

Furthermore, all VPS are supported by two engines:

1. LXC
2. KVM (supported from SERVERware version 4.5.0 and above)

KVM stands for Kernel-based Virtual Machine and is based on Firecracker, an open source virtualization technology specifically designed for the creation and management of secure multi-tenant container services.

With KVM, each VPS has a fully emulated or virtualized machine to run its copy of the Linux kernel, offering better isolation at the cost of some additional performance. From a security standpoint, this is a much better approach for distributing resources across multiple services and their users. 

SERVERware's KVM implementation can run unmodified Linux containers as VPSs, which can be either PBXware containers or Docker containers pulled as OCI images from Docker Hub and similar sources. 

Furthermore, it is possible to package and distribute service software using open standards and tools.

Follow this procedure to create a new virtual server:

1. In the Virtual Private Servers view, click the button Create VPS.

The dialog box Create VPS appears.

In the tab General, enter the information in the following fields:

• Type: the type of virtual server you want to create.
• Service: the service the VPS must provide. This field appears if you have chosen a VPS type that supports a particular service. Select the name of the service from the list.
• Template: the base version of the virtual server for the selected VPS type. Choose a template from the list.
• Partition: the partition to which the VPS belongs.
• Name: a descriptive name for the VPS.
• High availability: enable this option to allow the VPS to fail over to a storage host in the event of a failure.
• Exclude from backup: if this option is selected, the VPS will be excluded from backup operations.
• Enable protected mode: if this option is selected, only administrators will be able to manage the VPS (start, stop, restart).
• Include in Geo-redundancy: if this option is selected, a drop-down list of available replications will appear. You can select the replication from the drop-down list to add the created VPS to the replication cycle.
• Description: You can add a description to the VPS if needed.

Click the button Nextto access the tab Security/Security.

• Password: Manually enter the password (the existing password will not be displayed here).
• Generate a password: The server will automatically generate a new password.
• Security box: Check this box to confirm that the password has been copied to a safe place.

Click the button Nextto access the VPS resource configuration in the tab Resources.

In the tab Resources, enter the details in the following fields:

• Instance flavor: Choose a resource configuration suited to the needs of your VPS from the versions available in the list. Each version offers a specific resource ratio.
• CPU: Limit the number of CPU cores allocated per VPS. You can choose from the following values: • 1 • 2 • 4 • 6 • 8 • 10 • 12 • 14 • 16 • 18 • 20 • 24 • 28 • 32 • Unlimited

The default values for the CPU limits are inherited from the selected resource version.

• Bandwidth: Limit the disk read/write bandwidth in MB/s.
• IOPS limit: Limit the number of IOPS (input/output operations per second) per VPS. The default value is 150, but you can choose from the following options: • 50 • 100 • 150 • 500 • 1,000 • Unlimited

The default values for the read/write IOPS limits are also inherited from the selected resource version.

• AstDB RAM Disk: Enter the size of the RAM disk for storing the Asterisk database. This option only concerns PBXware-based VPS and should only be configured if you encounter performance problems.
• RAM disk for call recordings: Enter the size of the RAM disk for storing call recordings. This feature is specific to PBXware.

Mount points:

Allocation of the size of the folder mounted on /tmp for the VPS:

• Temporary directory size:
  The default value for all VPSs is 256 MB.
  The minimum value is 64 MB.

It is not recommended to allocate a temporary directory size greater than 50% of the RAM assigned to the VPS.

Allocation of the size of the folder mounted on /run for the VPS:

• Runtime directory size:
  The default value for all VPSs is 128 MB.
  The minimum value is 64 MB. 

It is not recommended to allocate a run directory size greater than 25% of the RAM assigned to the VPS.

Click the button Next to configure the VPS network in the tab Networking.

On the tab Networking, select the logical subnet to which you wish to connect the VPS.

Enter an IP address belonging to the selected logical subnet.

Click the button Next to display the tab Archiving (which will only be displayed if the archiving service is enabled on the partition).

Click the button Next to configure the DNS SRV + NAPTR records if this is configured.

The DNS lookup routine begins by searching for SRV records. Proper use of SRV records allows the administrator to distribute a service across multiple hosts within a partition, to move the service from one host to another without interruption, and to designate certain hosts as primary and others as backup.

To configure the DNS SRV record on the PBXware VPS:

Fill in the fields with the required data and press Save.

• Service :
  Symbolic name of the service. The service name is what the client accepts as a service (for the IP telephony service used, it is “_sip” or for TLS “_sips”).
• Protocol :
  Protocol used to access the service. SIP clients accept either “_tcp” or “_udp” depending on the client configuration. TLS will only work with “_tcp”.
• Target :
  Name of the partition associated with the resource record. In the partition name, we will enter the full path of our PBXware VPS, including the VPS name “vpsname.cluster1.serverware.xyz”.
• Priority :
  Service priority. Servers are ranked by priority, with lower priority numbers ranked before higher priority numbers. Set the priority to 0 if no priority ordering is desired.
• Size :
  Load balancing within the same priority. A higher weight number indicates that the server can handle more requests than a lower weight number. The probability of a server being ordered at the top of the list increases as the weight increases. Set the weight to 0 if load balancing is not desired. Otherwise, use non-zero values for all weights having the same priority. (An SRV record with a weight of 0 has a low probability of being ranked before an SRV record with a non-zero weight).
• Port :
  The port number assigned to the SIP service. This value would be “5060” or “5061” for TLS. Although it is preferable to use a single SRV record for each SIP server, some implementations may require multiple SRV records with a single service record for each resource name, because there are clients on “TCP” and others on “UDP” on the same service.

You can now save the configuration and start the VPS.