A VPS is a Virtual Private Server. You may hear them referred to as “Virtual Machines”, “VMs”, or in some provider-specific jargon, droplets or slices. VDS (Virtual Dedicated Server) is the same thing. We’ll call them VPSes here since, well, we’re VPSadvice! When you purchase a VPS, you’re buying a slice of a server – a virtual machine. If your needs were large enough, you’d buy a full dedicated machine (or many), but you don’t need that much, so you buy a VPS.
You’re allotted an amount of CPU, RAM, disk space, bandwidth, etc. You share the machine…in some senses:
- Your VPS will feel like a regular Linux (or BSD, etc.) server. It’ll have its own IP address, and if you’re supposed to have 1024MB of RAM, by gosh, when you run free -m you have 2048MB of RAM (assuming you know how to read the output). Although sleazy providers can play tricks, you should assume that your IP address, disk space, and non-burstable RAM are yours and yours alone (as long as you pay the bill).
- CPU is a bit mushier…some providers do sell dedicated CPU, so if you buy 2 dedicated cores and run then at 100% 24×7, that’s OK. But with most providers, you’re sharing CPU. Usually there isn’t an issue unless you become “abusive”. Some providers define that very specifically in their TOS/AUP (always worth a read), and many do not.
- Did I say your disk is all yours? Well…the disk space is, but the IOPS and disk performance is shared. Usual problems of either having a noisy neighbor or being a noisy neighbor.
- Your IP address is all yours – note that I didn’t say the network performance was. You’re on a server which probably has a 1gbps or 2gbps (or if you’re paying a lot, 10gbps) and you may have noisy neighbors.
- Your OS might be all yours. Depending on the virtualization, you may be free to install whatever OS you want, or you may be locked down to the providers’ templates.
Some things to think about when you’re shopping for a VPS.
Location? US, Europe, or…? Ideally, you want the VPS to be located near those who will be using it, to reduce network lag.
Operating System? Linux or Windows? BSD is another, less common option. Windows is generally more expensive because of the Microsoft license.
Managed or Unmanaged? “Managed” means your provider will assist in the system administration, or at least provide a lot of how-to help if you need it. This means that if Apache stops working or you need to upgrade MySQL or whatever, you can ask your provider for help. In some extremes, it even means you won’t have root access, though this is much less common. “Unmanaged” means you’re on your own. The provider will still troubleshoot any hardware issues, network problems, etc., but the actual care and feeding of the OS is your responsibility. Managed is generally significantly more expensive.
Do you need a panel, like CPanel? This typically adds $5-15 a month (with $15 being more common). Some providers will set it up for you. If not, you can always get one from BuyCPanel.com for $15/month.
Basic specs? This is memory, disk, and bandwidth at a minimum. You may not know what you need at the outset and of course, the nice thing about VPSes is that they can be easily scaled up.
Virtualization technology? Most people do not care if the virtualization technology is OpenVZ or Xen or KVM. But if you need to load a custom kernel module, etc., then you will want Xen or KVM.
How many IPs do you need? You will always get 1. Getting 2 is generally not difficult, though sometimes there’s an extra $1-$2 a month and you will need a good reason. More than that depends on provider availability and justification by you.
Do you need backups? The answer, of course, is “yes!”. If you plan to provide your own off-site backups, then perhaps you don’t need them provided by the VPS company. You really should have your own off-site backups.
Do you have a budget? If you’re limited to $10/month, then that pushes you into one category of providers. If you need a certain performance level and that’s more important than cost, that’s a different discussion. Have some idea of what your budget is.