Web Hosting Talk : Web Hosting Main Forums : VPS Hosting : Enabling VSwap in Centos6?

[ptudia]

Let me preface my entire article by saying that I'm a total newbie when it comes to everything that will come in this post.

About a week ago I decided to rent a VPS to run my own Minecraft server. I was doing my own thing, learning from youtube videos and the like, and managed to set up a website, databases, plugins, etc. all on Centos 6. Then I hit a wall.

My plan allows for 2GB of RAM, and 2GB of "VSwap." Now, when I purchased my server, I assumed vswap worked like burst RAM (i had seen this in another youtube video; it essentially acted like additional RAM).

Imagine my surprise when my server hit my 2GB limit and crashed; I was unable to recover it for quite a while.

So, if you guys are still reading: I can't find very much information on what Vswap is, or how to implement it. Any help would be greatly appreciated.

Other possibly necessary information: Centos 6, 64 bit. OpenVZ. SolusVM control panel.

On a side note, if anyone wants to come play with me, both the connection ip and website are bcraft.us

EDIT: Also since the first day I deleted my entire root directory and now everything starts with -bash-4.1# and never shows me what directory I'm in. Help with that would also be appreciated. Thanks!

[learningcurve]

what is vswap?

[Martin-D]

vSwap doesn't provide any additional ram, it artificially slows down the VE so that it acts like it's using swap.

http://wiki.solusvm.com/index.php/OpenVZ_VSwap

[ptudia]

I actually did read that page before and didn't understand it. That's why I came to the pros for help.

Would anyone like to explain it to me like I'm 5?

[Jono20201]

If your VPS is only 2GB then you must not start Java with the -Xmx/Xms2048MB command, as then Java will take all the RAM not leaving anything spare for anything else your trying to run, plus the systems overhead.

[ptudia]

So VSwap does not have a purpose? Can I not turn it on? Why did the host advertise it as
"4GB (Ram+VSwap)"
if it is only 2GB?

[ControlVM Technology]

Is your host using SolusVM?
Understand the model here http://wiki.solusvm.com/index.php/OpenVZ_VSwap

[Hsunami]

As HR-Martin said, VSwap artificially replicates the behavior of real swap. You're not actually swapping out pages onto disk, but your container will slow down as if you were.

Originally Posted by ptudia

So VSwap does not have a purpose? Can I not turn it on? Why did the host advertise it as
"4GB (Ram+VSwap)"
if it is only 2GB?

This is misleading. It should never have been advertised as 4GB. It's a 2GB VPS with 2GB of swap. Like a dedicated server or VPS based on other virtualization methods like Xen or KVM, you never want to get to a point where you're swapping. Everything will be slow. Sounds like you simply need a larger plan.

[SiteServing]

You can read more about vSwap here:

http://openvz.livejournal.com/39644.html