0

What Kind Of VPS Do I Need For A vBulletin Forum?

I’m asked this question pretty regularly, because vBulletin forums are often setup with shared hosting and fly under the shared hosting radar until traffic, robots and memory consumption bring the forum to the hosting provider’s attention which usually end up with the vBulletin forum being asked to leave.

When that happens, the vBulletin forum owner is in a state of panic fearful of the downtime and reputation of the forum being associated with downtime and scrambling for so many hosting options.

First, we need to find a VPS based on your forum’s needs.

If you are a small or brand new forum, this is good. I would recommend an OpenVZ VPS with probably 1gb RAM minimum, 2gb of burstable RAM, 30gb of disk space and 500gb – 1000gb of network transfer on a 100Mbps connection or better (such as shared Gigabit). You would need 2 CPU cores minimum, but I would recommend anywhere between 4 – 8 CPU cores total with a high clock speed. 8 AMD processors running at 1Ghz would work also.

This setup can run you anywhere from $10 – $30.

The reason I recommend OpenVZ for this situation is if you need more RAM, such as you doubled your forum membership or more active users are online at once, you can submit a support ticket to your hosting company and purchase another 1gb of RAM and more burstable RAM without rebooting your vBulletin forum.

If you chose Xen, which I recommend and see my point below, you would have to reboot your Xen VPS on each downgrade and upgrade so it could take anywhere from less than 15 seconds of downtime to 5 minutes depending on the node.

If you are a medium sized forum or expecting large amounts of growth through advertising, link exchanges with other forums, or are just a successful forum operator you should really look into Xen VPS hosting.

The difference between the OpenVZ example above and a similar Xen configuration is only about $5 more per month with the same resources but the advantages are tremendous. KVM is very similar to Xen and if your provider does not offer Xen but KVM, KVM is perfectly acceptable and highly recommended.

  • You do not share resources with other clients, like with OpenVZ.
  • If you are guaranteed 1gb of RAM, nobody else can take that RAM.
  • If you are guaranteed 2 or 4 CPUs, it’s yours for the taking.
  • Xen allows you to install kernel modules, such as PPTP.
  • Xen HVM allows you to recompile your own kernels*

*Note: most “Xen VPS” providers are Xen PV. Ask if they are Xen HVM. A good rule of thumb is if the provider offers Windows, which is not supported on Xen PV but with Xen HVM, that they can probably set you up with a Xen HVM account.

Second, we need to determine what hosting location will work for your vBulletin forum

If your forum has a majority of US members, why would you move your forum overseas to somewhere like Turkey or Romania? With the way the Internet works, a connection goes to another piece of networking equipment and is routed to another piece of equipment to eventually be transferred to your hosting provider’s data center and servers. In networking speak, this is called “hops”.

A good example of how hops work is a public transit bus. This bus goes all over town but needs to make stops at various points on it’s route. Each stop could be thought of as a “hop”, after that stop the bus goes to it’s next “hop” on it’s route until it goes to your destination where you get off the bus. This is not a perfect example but it gives you an example because most people do not understand how the Internet works.

If you host your vBulletin forum overseas, such as in the UK or Germany which I would recommend if you wanted to host your vBulletin VPS in an EU location, it takes on average an additional 75 – 150ms to leave the United States, go through an underwater fiber optic cable in the Atlantic Ocean and show up in a UK data center. If you move your location to somewhere like Turkey or Romania, this could take additional “hops” (or stops like in our bus example), which could increase the lag of your forum.

Your forum could be hosted on a $10,000 piece of server hardware with access to 128gb of RAM but if you’re hosted in a bad location, your forum performance will always be slow to visitors trying to access it.

Germany is a well connected country, with bandwidth everywhere, so I feel that its a good choice for vBulletin forum hosting. However, the UK does not have the same capacity in my experience as Germany. I’ve noticed that bandwidth is more expensive and not as plentiful with VPS hosting packages as German VPS servers. There is an extra 20-50ms delay between UK and Germany, so please consider this to the 75 – 150ms delay from the US across the Atlantic and into the EU.

In conclusion, vBulletin hosting on a VPS has great rewards over shared web hosting. You have dedicated resources, your own SQL server and can install requirements on your server to meet vBulletin or a plugin’s needs whereas if you were with a shared web hosting provider, they may or may not enable such a PHP requirement for a plugin as it would cause some downtime with their webserver.

However, since you’re running the VPS you are now technically the system administrator and the responsibility is with you, the forum owner, to maintain and operate your VPS server unless you hire a server management company or arrange for managed support for your vBulletin forum. If you Google “vBulletin consultant”, there are numerous companies willing to assist you with migrating from shared web hosting to virtual private server hosting, setting up a vBulletin forum on virtual private servers and even maintaining your forum. The advantage of a vBulletin consultant over a server management company or with your hosting provider is that the consultant has more experience with vBulletin as the management company or hosting company support staff only have limited experience with operating, upgrading and maintaining vBulletin which can be tricky sometimes.

Note: Please keep checking in as I will create a tutorial about how to setup a basic vBulletin forum on a virtual private server. Thank you

0

My Debian VPS Can Connect To SSH But Not Apt-Get Update

This is a common problem with Debian VPS servers that I see probably one third of the time when reviewing VPS hosting companies. I think it’s just oversight on a template and not anyone’s fault but kinda annoying sometimes.

A VPS company will send you login details, such as an IP, root password and SolusVM info, but when you login via SSH you cannot apt-get update or ping Google’s website but somehow can connect via SSH.

This is because your VPS does not have any nameservers set.

You can issue the following command:

rm -rf /etc/resolv.conf
nano /etc/resolv.conf

Add in the following lines and press Ctrl+O to save, then Ctrl+X to exit:

nameserver 8.8.8.8
nameserver 8.8.4.4

The final command:

/etc/init.d/networking restart

You should be able to run apt-get update or ping google.com to verify a working Internet connection.

0

What Kind of VPS Do I Need To Run WordPress?

This is a very common question and there are tons of information on the Internet about what the minimum requirements are and what to avoid so let me clear up some of the confusion.

This is part of an ongoing series of “WordPress Wednesdays” and in the month of October we will discuss on this website what kind of virtual private server do we need to run WordPress, a popular content management system that operates a significant amount of websites including blogs, websites just like this and even many news websites such as from CBS Local all run WordPress because of it’s flexibility.

OpenVZ or Xen?
A very good question indeed!

OpenVZ would be the bare minimum I would use for WordPress hosting while if you have a medium to large traffic website or require a lot of plugins, caching, etc. I would go with Xen VPS hosting for WordPress hosting which is generally only a few more dollars more in comparison to OpenVZ but the performance is worth those few extra dollars.

Hardware?
A VPS server’s CPU and hardware are often overlooked by individuals who are primarily focused on price!

WordPress is not CPU intensive, however MySQL which powers the WordPress content management system is, so if you go out and get a $3 VPS which has 128mb RAM, 10gb of disk space and only one CPU – do not be surprised if that medium or high traffic WordPress based website starts to crawl!

I’m sure you see guys on forums talking about they have WordPress running on a 32mb – 64mb VPS but please do not even consider shorting yourself on memory. If you want 32mb of memory dedicated to running your WordPress blog, why did you even leave shared web hosting?

A budget motivated website owner will get a custom VPS with more than enough RAM, disk space and bandwidth but only get one or two CPUs for a website that receives thousands of visits during peak hours!

Don’t short yourself on CPU!

To put things into perspective, how many single core processor desktops and laptops do you own?

If you own one, they’re slow as molasses when you’re trying to watch high definition video right? Same concept with a virtual private server – one CPU works for DNS servers, OpenVPN servers and web servers offering static files like images and HTML files but if MySQL is involved in your project and a dependency, 2 CPU cores are a minimum I would consider with 4 or more CPUs as what would be acceptable to me.

It does not matter if you have Intel Xeon or AMD based CPUs on your server. 8 CPUs at 1Ghz with an AMD based system is just as good as 2 CPUs running at 3Ghz on an Intel Xeon system.

The problem you had when you were on shared hosting running your WordPress site was your CPU and memory was limited. Most memory available to shared web hosting customers is anywhere from 8 – 32mb to run their PHP web applications. If you have multiple plugins, including a sitemap generator, this is where you would get all the weird errors, blank pages and what generally drove you away from shared hosting to virtual private server hosting.

Conclusion:
With our first lesson on “WordPress Wednesdays”, we have learned that OpenVZ and Xen does not really matter when it comes to running a WordPress site.

With OpenVZ, all the resources are shared with “your neighbors” on the same VPS node like shared web hosting and with Xen, your resources are guaranteed. Xen is only a few more dollars than OpenVZ but I think resource guarantees are worth the few extra dollars.

We also learned that CPU is something often overlooked by VPS hosting customers but should be emphasized more than anything. Would you drive a sports car if it only had a two cylinder engine inside of it that would be fast as a lawnmower or do you want the V8 engine, with 8 cylinders powering the sports car, which could be similar to an 8 CPU core system?

Thank you and tune in for next Wednesday’s article where we discuss if we should consider Apache or nginx with our WordPress website.

0

VPS OS: Which Linux Distribution is the Best?

There are sometimes overwhelming options for an operating system with virtual private servers and here is some information that may be useful for you to choose, if you are unsure, and some of the pros/cons of the operating system.

CentOS(homepage)
CentOS, short for Community ENTerprise Operating System (CentOS), is a fully Redhat / RPM compatible operating system but is community supported, not commercially supported like Redhat. This means the development team works together, takes input and patches from the Linux community and releases it.

The advantage of CentOS is that if you are transitioning from Redhat to CentOS or have a Redhat requirement, that CentOS will be 100% compatible with your requirement of a Redhat operating system.

I have ran CentOS for projects and I like it, if it’s a requirement, but since I was “raised” on Debian Linux I prefer it. However my personal opinion should not sway you from trying out CentOS.

There are a lot of blogs and websites dedicated to CentOS, the operating system is well documented, and the yum package manager is very easy to run, maintain and upgrade a virtual private server which is a big plus.

Debian(homepage)
Debian, named after Debra and the creator of Debian Ian Murdock (Deb + Ian), is a popular and widely used distribution of Linux. Debian has over 29,000 maintained packages available for download by their users and this operating system can run on a variety of hardware. Also, Debian can run the Linux kernel and the FreeBSD kernel. Debian running the FreeBSD kernel is called GNU/kFreeBSD.

The advantage of Debian is that it’s stable, actively developed by enthusiasts and developers, has over 29,000 actively maintained packages available for download from the apt repositories, and the package maintainers prefer stability over “latest release” software which may have bugs and could compromise the stability of the Debian server.

A disadvantage is a lot of folks who want the “latest release” of software find it’s unavailable and they have to use third party apt repositories, such as from the developer themselves or from third party repositories like DotDeb. This is generally why Debian users move from Debian over to Ubuntu, which is 100% compatible with Debian but the repositories are more up to date for the folks who want latest releases of software.

Ubuntu(homepage)
Ubuntu, or as I like to say “Debian’s cousin”, is based on Debian and uses the apt package/repository system but is more “cutting edge” and “up to date” than it’s Debian cousin.

Debian software will generally run on Ubuntu and vice versa.

The advantage, as I previously explained with Debian, is the software and repositories are updated, cutting edge, but could compromise stability if a package is not thoroughly tested by package maintainers or the developer of the package themselves.

I have not seen an issue from latest release software being buggy, but this is just a theory that could happen.

I run Ubuntu on my laptop and enjoy it tremendously as “latest release” packages will fix stability issues on desktop hardware which uses more software and packages than a virtual private server who may just run the minimal base operating system, a webserver, PHP programming language, etc.

The disadvantage? Ubuntu is just as solid as a desktop operating system as an operating system for servers and virtual private servers. I’ve never had an issue with packages, compatibility or stability with an Ubuntu operating system. Actually I have one Ubuntu based virtual private server with over 200 days of uptime.

Conclusion:
I have only mentioned 3 operating systems, such as CentOS, Debian and Ubuntu, because I only have experience with those operating systems. However in all fairness, I am going to start using and testing other operating systems in a virtual private server environment to give all operating systems a chance and report back to you.

0

OpenVZ vs. Xen vs. KVM – Which kind of VPS is the best?

This is a common question and a lot of people don’t understand that “one size fits all” does not apply when it comes to VPS hosting. It should be “one size fits most.”

OpenVZ:
OpenVZ, in my opinion, is a step up from web shared hosting but still has the shared hosting feeling because of shared resources. In my experience I notice the usual transition is that a shared web hosting customer will be kicked out or suspended from the hosting company for using too much I/O, such as attempting to run a forum or a heavy traffic WordPress blog, or the customer is tired of WordPress timing out on upgrades.

OpenVZ is cheap and is attractive to 99% of the interested customers however:

  • You have to share resources with your “neighbor” on the server.
  • If your “neighbor” has tons of traffic hit his WordPress blog, which puts load on his MySQL server, you and everyone else on the server is going to feel it because of the CPU demand.

Xen:
Xen, in my opinion, is the preferred VPS hosting that I recommend to individuals where the website has to be up, fast and reliable but the customer has the money in their budget to pay for the price difference. The difference is usually a few dollars and honestly, how much is your downtime or reliability worth?

Xen comes in two options: Xen PV and Xen HVM.

Xen PV, or paravirtualization, is like OpenVZ in the fact that Xen uses templates like OpenVZ and reinstalls can be done from the control panel.

HVM allows you to mount and install an ISO, like a dedicated server, and gives you more options for operating systems like *BSD operating systems that are not supported by OpenVZ. Xen HVM supports Windows and is how most Windows VPS servers are powered.

KVM:
KVM is a popular alternative to Xen and just as recommended as Xen. I have no personal preference between Xen and KVM except that if Xen HVM is unavailable and you need to install from ISO, that KVM is just as good as Xen HVM.

The pricing is generally the same between KVM and Xen HVM.

Conclusion:
With all the available options, if you are looking for a “step up” from shared web hosting to a virtual private server and lack the system administrator experience, OpenVZ is a good choice. Also, if you have a limited budget OpenVZ is just a good choice.

If you need something as easy to use as OpenVZ but want reliability, Xen PV is a good choice for a few dollars extra to get better, guaranteed resources and a more reliable VPS than OpenVZ.

If you want customization of installing your own ISO or Windows VPS, Xen HVM or KVM is good. Both are as equal and reliable so I have no personal or professional preference.

0

Xen or OpenVZ – Which is faster, and which is better?

The question is often asked whether OpenVZ or Xen, two of the most common hypervisors in VPS web hosting, provides a faster hosting environment.

Hypervisors

The most common answer to this question is that “OpenVZ is faster,” even though this is not strictly true. OpenVZ’s virtualization is managed at the operating system (OS) level, compared to Xen’s paravirtualized or fully hardware-virtualized environments. Hence, OpenVZ requires slightly less resource overhead, and can be seen as a more resource-efficient hypervisor — but not necessarily a “faster” one.

Compared to performance that would be measured for an application running directly on the physical server, all virtualization techniques will result in at least a small loss in performance due to the hypervisor’s resource overhead. Since most VPS hosts power their host servers with high-quality hardware, this loss in performance is hardly perceptible.

However, the question remains as to whether the Xen or OpenVZ hypervisor achieves better performance. The simple answer is that there are a great number of factors which could determine an answer one way or another, but there are certain key factors which set the two system apart.

 

Resource Availability

It is important to note the methods Xen and OpenVZ use to assign resources to VEs. On an OpenVZ host server, where all of the server’s physical hardware resources “belong” to the host server and VEs differ only in the operating systems they are running, each VE will essentially have access to the entire server’s resources. Although there are “soft limits” placed for each VE to prevent over-usage of RAM, disk, and other resources, these limits can be (and are frequently) bypassed and abused. For this reason, the performance of an OpenVZ VPS can vary wildly depending on how many other VEs are on the same host, and what they are doing.

In contrast to OpenVZ’s OS-level virtualization, Xen virtualizes hardware and network resources at a deeper level, and provides near-total isolation for each individual VE. It is well-known that Xen VPS instances can run their own isolated kernels, but this more advanced hypervisor confers other benefits as well. A Xen VPS is guaranteed its resource allocations in such a way that it is impossible for neighboring VEs to “steal” them, which means that Xen environments are far more reliably stable than OpenVZ environments.

 

Resource Over-commitment (Overselling)

A side-effect of these virtualization techniques is that Xen host servers cannot be oversold, while OpenVZ host servers are frequently oversold (in fact, this is why OpenVZ hosting is typically less expensive than Xen). Overselling is the practice of over-committing the host server’s resources in such a way that the server could not actually sustain itself if each VE requested 100% of the resources it is “guaranteed.” Since Xen dedicates resources to each VE which are then no longer available to the host system or any neighboring VEs, it is not possible to over-commit a Xen host’s resources.

 

Security & Stability

For the same reasons mentioned above — namely, that OpenVZ containers take their resources freely from a “pool,” while Xen containers have their own dedicated resources — OpenVZ is also prone to flaws impacting system security and stability.

Since OpenVZ virtualizes at the OS level, all hosted VEs essentially share the same host-level kernel. Because of this, a kernel exception caused by one container can crash the entire host server, affecting all other co-hosted VEs. Similarly, OpenVZ hosts use a single iptables and single network interface to mediate incoming/outgoing connections, as well. The results are easy to imagine: if one VE pushes too hard (even accidentally), the others will suffer.

Each Xen environment is “locked in” to its container, which makes it comparatively impossible to abuse the host system in a way that would affect neighboring VEs. For this reason, Xen VPS are considered far more reliable and secure, and can be likened more to dedicated servers in terms of their structure and features.

Conclusion

With all of this in mind, it becomes clear why OpenVZ is often said to be faster than Xen, and sometimes even appears that way in benchmarks — the benchmarks compare [b]empty OpenVZ systems to empty Xen systems, as would be typical in an objective, testing environment.

In a real web hosting environment, however, host servers will be bustling with activity by the time you get there, which makes a Xen VPS is a much better guarantee to have — it means having the peace of mind knowing that the resources you need will be there when you need them.

Although it is true that OpenVZ is marginally “faster” due to the hypervisor’s decreased resource overhead, this difference is not tangible in actual usage, and will manifest only as a slightly smaller amount of available RAM on freshly installed Xen VEs.

So, here is the final answer:

In Theory, OpenVZ provides a faster virtualized environment due to the fact that the VE is directly supported by the host system, and therefore uses less of its own resources to maintain its OS.

In Practice, Xen reliably outperforms OpenVZ, especially among budget-oriented web hosts where practices like resource over-commitment are common.

 

This article is also available in the VPS6.NET Knowledgebase: https://vps6.net/my/knowledgebase/69/OpenVZ-or-Xen-VPS—Which-is-faster-and-which-is-better.html

0

How to Check VPS Memory/RAM Usage

In the course of monitoring your VPS, one of the first things you will want to check is RAM (memory usage). Linux includes a few easy-to-use tools, including free and ps, described here:

The simplest memory reporting tool is free. To use it, simply run:

# free -m

You will see an output like this:

total       used       free     shared    buffers     cached
Mem:           512        462         49          0         46        127
-/+ buffers/cache:        287        224
Swap:         2047          0       2047
The most important figure to look at is the value under “used” in the “buffers/cache” row. This will tell you how much RAM your processes are currently using, in megabytes. Memory fork errors will occur if the total amount of memory and swap space is lower than this number. To see how much RAM is free, check the “free” column in the “buffers/cache” row.
Another useful tool is ps, which will show you the percent of total RAM used by each running process:
# ps aux
Sample output:
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.1  10368   632 ?        Ss   Jan07   0:00 init [3]
root         2  0.0  0.0      0     0 ?        S<   Jan07   0:00 [migration/0]
root         3  0.0  0.0      0     0 ?        SN   Jan07   0:00 [ksoftirqd/0]
This article is also available in the VPS6.NET Knowledgebase:
0

OpenVZ vs. Xen: What’s the difference, and which is better?

We’ve written this article to provide a little insight and guidance as to the difference between Xen and OpenVZ, two very popular but somewhat different virtualization technologies. Ultimately, as with choosing between a Linux or Windows server, you will need to think about the applications you will be running to decide whether OpenVZ or Xen will be a better fit for you. Below is a brief summary of some of the key differences between these two platforms.

The slightly more reliable virtualization software is Xen, a para-virtualization platform that creates virtual servers with almost exactly the same characteristics as dedicated servers. A Xen VPS will run its own isolated kernel, load its own kernel modules, use fully dedicated virtualized memory, I/O and scheduler, and will be just as stable and extensible as a dedicated server. You’ll never know that you’re only using a virtual server — for a small premium.

OpenVZ, on the other hand, is an operating-system-level virtualization platform that works in much the same way, but provides only a thin layer of virtualization on top of the underlying OS. All virtual servers on an OpenVZ node will share the same core Linux kernel–this is why OpenVZ only supports Linux OS templates–, and, consequently, will also suffer alike from issues like kernel crashes. Despite these small drawbacks, OpenVZ is more cost-effective, easier to understand, and usually performs much better for small virtual servers, due to having the extra resources available that a Xen VPS would be using to run its completely isolated environment.

Main Features of OpenVZ Virtualization:

+ Full root access.

+ OS-level virtualization.

+ ‘Burst’ RAM and other extra resources available when nodes are underused.

+ Upgrades can be applied on-the-fly, without reboots.

+ More resources available due to lightweight virtualization.

+ Simple network and disk setup.

+ Access to most iptables modules.

Main Features of Xen Virtualization:

+ Full root access.

+ Supports Linux and Windows.

+ Better Java performance.

+ Resources (RAM, etc) are fully dedicated and private.

+ Para-virtualized Linux kernel (i.e., full isolation).

+ Direct access to loadable kernel modules.

+ Swap space.

+ Highly configurable.

If you are in doubt about which platform would be better for you, OpenVZ will most likely offer an easier-to-setup and more cost-effective solution, unless you know in advance that you will require specific kernel modules that OpenVZ may not support.

This article is also available in the VPS6 Knowledgebase:

https://vps6.net/my/knowledgebase/12/OpenVZ-vs-Xen-Whats-the-difference-and-which-is-better.html