VPS Hosting Guide For Beginners

VPS Hosting Guide for BeginnersWhat is a VPS?

VPS stands for Virtual Private Server.

A VPS is a type of server that makes use of Virtualization technology to split physical server hardware into several ‘virtual’ servers hosted on the same physical infrastructure.

Whereas in the past system administrators were traditionally confined to using one physical server for one purpose only, virtualization offers the flexibility to host several servers on one physical server. Each server can have it’s own purpose and it’s own distinct operating system.

This dramatically improves the level of flexibility available to system administrators in terms of the choice of software configuration they can run as well as providing significant advantages of scalability in terms of processing power, RAM and disk space and at a lower cost than using traditional dedicated physical hardware.

This document will help the reader to understand the key technologies underpinning the VPS option and allow them to make an informed purchasing decision.

Types of Hosting

A VPS sits between Shared and Dedicated Server hosting and offers several benefits over each.

See: What is Shared Hosting? Explained

First let’s look at Shared Hosting and Dedicated Servers.

Shared/Reseller Hosting

Shared web hosting is an entry level hosting service. It offers one operating system (e.g. Linux) running a particular distro (e.g. Centos) and has a standard software configuration that the majority of clients will use (e.g. cPanel, MySQL, PHP).

As the name suggests, shared hosting is provided on a shared hosting platform. That means that all clients share the server’s key resources such as CPU, RAM and Hard Drive (HDD).

With Reseller Hosting it is the same infrastructure but the client has the possibility to resell on the space to their clients without having to make a big investment in hardware or software.

Shared hosting is low cost and offers a standardised, uniform web hosting environment that will suit most clients. There is little room for customization or running non standard applications.

If you use a reputable host then you should also be hosted on high spec servers which have better levels of redundancy built in such as dual power supplies, dual CPUs, multiple disks in hot swap RAID (Redundant Array of Inexpensive Disks) configuration.

Security and administration is the responsibility of the hosting company.

The main advantages of shared hosting are:

  • Low cost
  • Standard level of performance
  • High Spec equipment and configuration
  • Standardised configuration
  • Low level of client administration required

On the downside, users are limited to the software specification of the hosting company. They may not be allowed to run certain applications that require configurations outside of the standard parameters (i.e. latest version of PHP) or use some features that are restricted for security purposes (i.e. SSH access).

Shared hosting also means that performance may be affected by ‘noisy neighbours’ who abuse the server’s resources. This can be reduced if your hosting company uses a resource limiting software.

Finally, with shared hosting it is possible that the IP reputation of the server could be impacted if the web hosting company does not monitor their servers closely for any malicious traffic or email. Rogue accounts or insecure websites can result in Malware being uploaded and deployed from the server.

The best way to reduce this possibility is to check that your hosting company monitors and filters all outgoing mail to identify and prevent spam from being sent to protect the server’s IP reputation.

Here at Pickaweb we monitor our servers very carefully and thoroughly using tools like Spam Experts.

So in summary Shared/Reseller hosting is a low cost, entry level service with limitations on the amount of resources and possible customization.

Dedicated Servers

A Dedicated Server as it’s name suggests is a physical server which is dedicated entirely to one client. No other websites or applications can be hosted on the server.

This means that the client gets exclusive use of all of the server’s key resources, i.e. CPU, RAM and HDD. The client can install their choice of operating system (e.g. Linux, Windows) and the Distro of their choice (e.g. Ubuntu, CentOS).

The advantages of a Dedicated Server are as follows:

  • High reliability
  • High performance
  • High level of security
  • Better IP reputation (not sharing with other websites)
  • No sharing means no noisy neighbours

On the downside, Dedicated servers are a more expensive solution. They offer significantly more more power but if extra resources are required (i.e. CPU, RAM, HDD) then in the best case this will involve downtime to upgrade the components and in the worst case it will require a migration to a new physical server.

Another consideration is building redundancy into the server. What this means is minimising the possibility of downtime caused by component failure. In a dedicated server there are two mechanical components which may cause downtime. These are the Power Supply Unit (PSU) and the HDD (the exception would be Solid State Drives (SSDs) – these are electronic components and have a much lower failure rate).

It is possible to mitigate against this by using dual components and in the case of some RAID configurations (i.e. RAID10) this can involve a minimum of 4 physical hard drives. This means a) extra up front investment and b) more ongoing costs due to the larger chassis (typically 2U) required for the extra components.

Finally, Dedicated Servers usually take a couple of hours to provision from an order being received to the server being live and configured with the base operating system.

Common Types of VPS Configuration

So we can see that at one end of the spectrum there is Shared and Reseller hosting which are low cost and standardised offerings.

At the other end of the spectrum there are Dedicated Servers which offer much more power and flexibility.

Before we explain the benefits of a VPS over these options, it’s first worth considering how VPS are setup.

Single Server VPS

With this type of VPS a single physical server is split into several ‘virtual’ servers using a Virtualization software.

The advantage of this approach is that it is low cost to the hosting company as only one server is required to start offering VPS and only one licence is required. These savings can be passed on to the client so that the client has a low cost VPS option.

The downside of this approach is that everything is hosted on one server so there is the need to build redundancy into the server with dual CPU’s, Dual power supplies and hot swap hard drives configured in a RAID array. This may push the cost of the service up.

This approach does not offer any High Availability (HA) either as the server represents a single point of failure. What this means is that should the server experience a catastrophic issue which brings it down for any period of time then all clients on the server are affected.

Also this type of configuration is not suitable for live upgrades. For example, if more RAM is required this will require downtime to power down the server and add the extra RAM.

Multi Server (Cloud) VPS

A Multi Server (Cloud) VPS configuration avoids the single point of failure issues of a single server VPS by pooling together the resources of several servers. The processing and data storage capacity of all of the servers in the cloud configuration offers a truly scalable and resilient infrastructure.

This type of VPS configuration is more complex to set up than the single server VPS option, but it offers both the hosting company and their clients some significant advantages:

  • High Availability of data – data is stored on several separate servers
  • High Uptime – no single point of failure
  • No downtime upgrades
  • Live migrations
  • Different disk types can be offered (e.g. SAS and SSD)
  • Instant provisioning (minutes to setup a VPS vs hours for Dedicated Server)

Pickaweb offers the Multi Server (Cloud) VPS configuration on both our standard VPS and (SSD based) Cloud SSD VPS. We do not offer single server VPS options.

What is really important to understand is that the Cloud VPS pools together the resources of numerous servers and can be scaled to dozens or hundreds of servers.

This means that data is spread across the cloud and processing power is shared. It is a very elegant and resilient solution. Because data is stored across several physical servers, the possibility of downtime or data loss are dramatically reduced. If one server fails completely the rest of the cloud continues working and the data is safe. Once the failed server is fixed it is brought back online and back into the server. The client will never notice any interruption in their service.

VPS vs Dedicated Server

If you feel that you definitely need more power, security and flexibility than shared or reseller hosting offers then you need to decide which option is best for you: a VPS or a Dedicated Server.

We have prepared the following table to illustrate the main differences between the two options.

 

Characteristic

VPS

Dedicated Server

Control

Client has control over virtualized machine on cluster with several other virtual machines

Client has full control of single physical server with admin access to all the server resources

Resource Availability

CPU is shared with other VPS, but uses dedicated RAM and HDD

Has all CPU/RAM processing power & HDD assigned to single user with no sharing

Software Customization

Client has total admin & root control. Software configuration can be to customized to their needs

Client has total admin & root control. Software and Hardware configuration can be to customized to their needs

Migration

VPS migration within the local cluster is quick and straightforward.

Migration between physically separate servers is more time consuming

Scalability

Cloud VPS are extremely scalable. Possible to add or decrease RAM, CPU & HDD in real time with no downtime

Physical intervention required. Upgrades and downgrades can result in downtime.

Cost

Extremely cost effective. No/low upfront cost. Pay for what you use.

Higher up front and ongoing cost. More expensive if resources are underutilized

Deployment

Fast. Less than 2 minutes deployment typically

Slower. Approximately 2 hours

High Availability (HA)

HA possible with Cloud VPS. Data stored across several servers. No single point of failure

Limited possibility for HA. Redundancy limited to server level (dual power supplies, network cards, CPU, RAID, hot swap arrays). This makes it a higher cost option. HA would require clustered server setup which would increase startup and ongoing costs

Security

Root access to VPS ensures nobody can access your data. Hosting company has master admin rights to their cloud so they have overall control.

Client has full control over the physical server. Nobody else has any master rights over the server. Full control is possible.

In summary then the VPS has the following advantages over a Dedicated Server:

  • Instant deployment – no waiting
  • Lower cost of entry
  • Cost effective – pay for what you use
  • Flexibility – upgrade or downgrade to your exact requirement
  • Fast migration possible
  • High Availability at a reasonable price

The one area where a Dedicated Server has a slight advantage is in cases where belt and braces security is required. This is more to do with regulatory or compliance issues than with any inherent security issues with a VPS.

Hard Disk Drives (HDD)

When choosing your VPS you need to consider which type of HDD to use. In general there are three main types of HDD available to you when you chose a VPS:

⦁ SATA (Serial Advanced Technology Attachment)*

⦁ SAS (Serial Attached SCSI)

⦁ SSD (Solid State Drives)

* Please note that Pickaweb does not offer SATA VPS (or SATA Shared or Reseller Hosting). They are included here for completeness to illustrate the differences typically available on the market.

When choosing your VPS it is important to understand the characteristics of each type of storage.

They can be summarised as follows:

  • SATA: Solid, reliable traditional disks with high density storage capacity but slower data read/write capabilities. Typically used for budget hosting or backup
  • SAS: High reliability, faster enterprise hard drives with higher read/write performance but lower storage capacities. Perfect for performance hosting at a reasonable cost
  • SSD: Completely electronic and with no moving parts, SSD offer a huge jump over mechanical, spinning disks in terms of performance and reliability. The future of data storage

Below is a table which shows the difference between them.

 

Feature

SATA

SAS

SSD

Disk Rotational Speed (per minute)

7.2k or 10k

10k or 15k

Not Applicable

IOPS (Input/Output Operations per second) – a common method for measuring disk performance

~ 80 io/s

10k – ~ 120 io/s

15k – ~ 180 io/s

Random read – 75000 io/s

Random write – minimum 4600 io/s

Energy Usage

~ 8.7 watts

~ 15 watts

~ 5 watts

Mean Time Between Failure (MTBF)

700,000 to 1 million hours

1.2 million to 1.6 million hours

2 million hours

Storage Capacity

Upto 8TB

10k – 300GB to 1TB

15k – 300GB to 900GB

120GB to 480GB

 

Which HDD Should You Choose for Your VPS

Currently Pickaweb offers SAS VPS and SSD VPS. Below are the points to consider when making a decision between SAS and SSD.

Why choose SAS HDD?

  • Good balance of speed and reliability
  • Suitable for demanding applications where cutting edge speed is not an absolute requirement
  • Enterprise Grade hard drives – proven, reliable and cost effective technology
  • Lower price than SSD but excellent performance

Why choose SSD?

  • The fastest type of storage technology – hundreds of times faster than traditional storage
  • Ideal for demanding ECommerce applications where speed is vital
  • Gives you a definite speed advantage of over competitors
  • Ultra reliable – no moving parts
  • Green credentials – less power usage
  • Future Proofing – SSD is the future of data storage

Operating System

When choosing your VPS you can select the operating system of your choice and your VPS will be provisioned (within 2 minutes) with your choice of Operating System (OS) from one of the following:

  • Centos (with cPanel* control panel or LAMP – Linux, Apache, MySQL, PHP)
  • CloudLinux* (with cPanel or Plesk control panel or LAMP)
  • Debian
  • Ubuntu
  • Fedora
  • Gentoo
  • Red Hat Enterprise Linux
  • FreeBSD
  • OpenSUSE

OS marked with * denotes additional licensing charges apply.

Backups

When choosing a VPS it is vital that you have a backup strategy in place. Backups are not just for security in terms of recovering data in the event of server hardware. Backups are also important in case data is accidentally deleted.

Pickaweb’s VPS offer the ability to backup data locally so that it can be managed and restored by the client via their billing area. This puts the client in full control so that restores can be managed without the need for technical assistance.

Datacenter

Pickaweb’s VPS are hosted in a Purtpose Built Tier 3 Datacenter close to Central London.

Here are the key points:

  • 70,000+ sq. ft purpose built facility with fully trained staff on site 24/7/365
  • 24 x 7 on‐site security team
  • 8MVA incoming power supply to site via 11kV EDF ring
  • Average Power Density 1.5kW/m² in technical area
  • Dual A & B supplies to all data halls & racks
  • Dedicated N+N in line UPS
  • Centralised N+1 HV diesel generators with 72 hours on-site fuel availability
  • Chilled water system N+1 air‐cooled chillers for technical and plant areas
  • N+1 computer room air conditioning (CRAC) units in each data hall with A & B supplies
  • 800mm floor void
  • 6 self contained Data Halls inside the facility
  • On-site build room/storage room
  • Various carriers offering totally resilient connectivity
  • Diverse fibre entry points to datacenter
  • 3 metre high exterior perimeter fence
  • Fully manned (vehicle) entry gate to site with security bollards
  • Complete CCTV site coverage (internal and external)
  • Leak detection system
  • Environmental monitoring system
  • Biometric access control system
  • Centralised N+1 water mist fire suppression system with VESDA detection
  • Green credentials – PUE of < 1.7

For full details please visit our datacenter page.

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