Xen VMs : Pre-Sales Technical FAQ

Why Xen?

We looked at alternatives such as User Mode Linux (UML) and Virtuozzo however the case for Xen was outstanding in terms of performance overhead, reliability, industry support and engineering excellence. Read about Xen's background and technology.

Terminology

VM: Virtual Machine. Each customer has root access to their own VM which co-exists with other VMs on the physical host server.
Host Server. The physical Dell server which has multiple VMs running on it. Only Xtraordinary can adminster the host server.
VPS: Virtual Private Server. This is a common marketing term for a Virtual Machine. VPS = VM.

Can I upgrade between plans?

Yes. Just email us at support @ xtrahost.co.uk. There is no set-up fee but you are committed to the new plan level for at least a further month.

Depending on available host server capacity an upgrade may require moving your VM to an alternative host server. If this is required then 20-30mins downtime for your VM will have to be scheduled.

Can I add memory or disk space?

Only by upgrading to a higher specification plan.

How much of my allocated disk space can I use?

Out of your disk space allocation you must allow space for your linux distribution and space for any installed applications.

How much swap space can my VM use?

As standard we set up VMs with swap space equal to 2 times the VM's physical memory (e.g. a VM-128 plan with 128MB ram gets swap space of 256MB). You can increase your swap space up to the available free disk space in your VM. Contact our support team if you need advice on swap space.

How many Domains can I host?

Unlimited.

Is a control panel available as an option?

cPanel is available at a cost of £8pm +VAT on Fedora Core distributions.
cPpanel is only available at time of original order, it cannot be added later unless a full reinstall is requested. Read more about our cPanel VPS.

Otherwise if you have the appropriate license you may install webmin, direct admin etc.

Who is responsible for backing up the VM?

The customer is responsible for taking an off-line backup of their VM contents. Xtraordinary accepts no liability whatsoever for content hosted on VMs.

How many VM are on each physical server?

Typically each server has around only 7-10 VMs hosted per processor core. Each host server has 8GB of physical memory of which 1GB is reserved for the host Xen system and 7GB is assigned to VMs.

Memory, rather than processor resources, is typically the constraint on performance for a VM. Our Xen host servers run under low CPU load.

Which Datacentre are the Xen VM Servers Hosted In?

All new Xen plans are now hosted in London, TeleCity Sovereign House.

What version of Xen are you using?

Currently new VMs are running Xen 3.04

Do you offer IPv6?

Not at present. Let us know about your IPv6 needs.

Are my IPs shared with other customers?

No. Each VM has its own assigned IPs.

How many IPs can I have?

Each VM has two IPs included as standard. If you require more you can request additional IPs subject to providing suitable technical justification and pay £5+VAT set-up fee for each additional IP. If you have questions please email sales @ xtrahost.co.uk

Will IPs assigned be consecutively?

Yes, except for cPanel orders or where a prior special request has been made.

Can you give me IPs spread across lots of different subnets?

No.

What are acceptable reasons for requesting additional IP addresses?

• Any service that needs its own unique IP.
• Acceptable reasons can include: - SSL certificates. - Secondary DNS server.
• Where it is possible to run services on different port numbers you should do that, do not request additional IPs for services that could quite easily run on a single IP with different port numbers.

Can I specify my Reverse DNS assignment for IPs?

Yes, this information is collected during on-line sign up.

Do you offer free trials or money back guarantees?

Trial periods will be considered on a case by case basis. Email sales @ xtrahost.co.uk outlining the purposes your VM will be used for.

Do you offer Windows VPS hosting?
Yes, more details are available on our Windows VPS hosting website .

What technical support is included?

If you have evidence of VM reliability issues due to problems with the host server, we will support you in troubleshooting those issues.

Technical Issues Not supported

Performance and reliability issues within the VM. Installing linux. General linux advice.

How will I receive my root password?

During our SSL secured on-line signup process you will be requested to select your own root password. Your root password must be at least 8 characters long and contain a mix of alpha and numerical characters. We do not send passwords in plain text emails.

Do you offer load balancing?

Not at present.

Do you monitor the servers?

We monitor the host physical servers. Customers are responsible for monitoring their VMs.

Is there a Service Level Agreement (SLA)?

Yes, a 99.9% SLA applies to Xen VPS services.

In the event of the total periods of Downtime, due to failure of the hosting service, in a calendar month during the Term, exceeding 0.1% of time in said month a service credit will be made. One full day's credit of the Service Fee will be given for each hour of Downtime beyond the 0.1% allowable, up to a maximum credit of 100% of the month's Service Fee.

The maximum overall service credit payable due to Downtime in any calendar month will be 100% of the month's Service Fee.

What are your strengths compared to competitors?

See our Xen VPS Hosting Checklist.

Acceptable Use Policy

Highlights:

• No IRC.
• No adult content permitted.
• No antisocial behaviour permitted (e.g. SPAM, spamvertised sites, scanning, illegal content..)

Read the full AUP here.