How do I find out if my system support Intel - VT / AMD -V hardware virtualization extensions for host CPU using the command line options?
Both Intel and AMD CPU support virtualization technology which allows multiple operating systems to run simultaneously on an x86 computer in a safe and efficient manner using hardware virtualization. XEN and other virtualization software can use Intel / AMD hardware virtualization for full virtualization. In other words with Intel VT, or AMD-V you can run an unmodified guest OS, like MS-Windows without any problem.
Use the following command to verify that if hardware virtualization extensions is enabled or not in your BIOS.
Linux: Verify Intel VT CPU Virtualization Extensions
Type the following command as root to verify that host cpu has support for Intel VT technology, enter:
# grep --color vmx /proc/cpuinfo
Sample outputs:
Fig.01: Linux check Intel VT - if my server can run full virtualization or not
If the output has the vmx flags, then Intel CPU host is capable of running hardware virtualization.
Linux: Verify AMD V CPU Virtualization Extensions
Type the following command as root to verify that host cpu has support for AMD - V technology:
# grep --color svm /proc/cpuinfo
Again, the output has the svm flags, then AND CPU host is capable of running hardware virtualization.
Tip # 1: Check Your BIOS Settings
Many, system manufacturers disable AMD or Intel virtualization technology in the BIOS by default. You need to reboot the system and turn it in the BIOS.
Tip # 2: XEN Kernel
By default, if you booted into XEN kernel it will not display svm or vmx flag using the grep command. To see if it is enabled or not from xen, enter:
cat /sys/hypervisor/properties/capabilities
You must see hvm flags in the output. If not reboot the box and set Virtualization in the BIOS.
- 30 Handy Bash Shell Aliases For Linux / Unix / Mac OS X
- Top 30 Nmap Command Examples For Sys/Network Admins
- 25 PHP Security Best Practices For Sys Admins
- 20 Linux System Monitoring Tools Every SysAdmin Should Know
- 20 Linux Server Hardening Security Tips
- Linux: 20 Iptables Examples For New SysAdmins
- Top 20 OpenSSH Server Best Security Practices
- Top 20 Nginx WebServer Best Security Practices
- 20 Examples: Make Sure Unix / Linux Configuration Files Are Free From Syntax Errors
- 15 Greatest Open Source Terminal Applications Of 2012
- My 10 UNIX Command Line Mistakes
- Top 10 Open Source Web-Based Project Management Software
- Top 5 Email Client For Linux, Mac OS X, and Windows Users
- The Novice Guide To Buying A Linux Laptop
{ 18 comments… read them below or add one }
Useful topic, thanks Vivek, and I didn’t know of “–color” fro grep, nice too.
Please give us some more topics related to virtualization, pleeeease !!! :-)
– Philippe
We have covered XEN, Vmware server and OpenVZ in the past.
However, I’m going to write a bit about central storage for VM, VM live migration, KVM (which seems like a winner to me), VM security & advanced networking in coming days. Let me know if you want to see any specific topics here or at vivek at nixcraft dot com.
HTH
It is possible that your processor supports virtualization while BIOS disables it (as mentioned) but have no option to enable it! That was the case with my Acer Aspire L5100.
I wrote about this problem and how I solved it:
Link
Interesting read; this is the main reason why I stick to Intel or Supermicro motherboards for server usage They never do this kind of silly stuff. I paid for it and I’ve full right to use hardware.
Vivek, how do I find if my processor can use a 64-bit version of Arch Linux or for that matter any Linux ? I got from my vendor as 32-bit. Someone on IRC told me something similar. Please help me out.
Run
If you get lm (long mode); it means 64 bit CPU. See this FAQ.
$ kvm-ok
Yes, but it is Debian / ubuntu thingy (script). So it is better if one learn to use direct command ;)
Hey Vivek,
I agree. But lets keep it posted, maybe someone can find it useful :)
Thanks Solaris I did find it useful…. I was unable to run virtual machine on my comp and was thinking that there is problem with my installation but then kvm-ok returned that virtualization is disabled from my BIOS…
Thanks. Got it from some referencing posts on your blog. You rock man.
hi ,if am planing to run full virtulasions ,do i need intel VT or AMD-V to make that work ?
Yes, you need Intel VT for Intel CPUS and AMD V for AMD CPUS.
Shouldn’t it be possible to use paravirtualization? Will need tweaked kernels but those are available.
Thanks,
- Milind
Hey,
What about taking many physical servers and making from them a single “super server” via Xen/VMware? Is there any article/guide that explains how to do so?
* When I say “super server” I mean to take 1 physical server and make him the “master” (where the OS sitting on, i.e – linux) and the other pysical servers are the “guest” (they have no OS (or just not regular OS, i.e – linux)
Thanks ;-)
actually i am new to this tech stuff. i dont know whats all this about but want to know more. were do you write these commands if you are running windows xp
ok, so I have the exact same CPU, Intel E8400, that you have. I have enabled Virtualization Technology in the BIOS. But I still do not see, vmx, when do this: grep –color vmx /proc/cpuinfo
But I do see hvm when do this:
> cat /sys/hypervisor/properties/capabilities
> xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64
What does this mean? I have VMX or I don’t ?
Though I have compiled the linux kernel 3.0, is it possible that it might be disabled in the kernel?
Yes, it is possible that some options may not been included in your kernel config.