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CiscoKid
Enthusiast
Enthusiast

Paravirtualization - ESX 3.5

Anyone have any working examples of using the new feature in ESX 3.5 with the Paravirtualization? I see that it annotates that it will only improve performance for OSes that can use VMI...is there documentation on that list of OSes? I am just curious. Thanks.

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uslacker99
Expert
Expert

I've run Ubuntu 7.1.0 with VMI and it works great. The time keeps up without having to mess with NTP or anything. I would recommend running NTP in production though. You can get a maximum of a 30% performance gain, but it's probably unlikely.

Just check the box for VMI under advanced options when the VM is down and you should see VMI if you grep for it in /var/log/messages after it comes back up.

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CiscoKid
Enthusiast
Enthusiast

Any advantage that you know of with running paravirtualization on a Windows based system?

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uslacker99
Expert
Expert

No windows paravirT yet.

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tomaz
Enthusiast
Enthusiast

I get a message that my CPU does not support long mode when enabling it for Ubuntu server 7.10/amd64. Not sure whether this is BIOS config problem (on DL380G5) or what.

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EvilGenius
Contributor
Contributor

Got the same problem with 64-Bit Ubuntu and paravirt. (... doesn't support long mode) here. Any solutions yet?

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kevin7
Contributor
Contributor

You have to use an AMD 64-bit CPU or and Intel CPU that suppots EMT64 (VT). We use the Intel Quad-core E5335's, and HP does not enable the VT emulation by default. Had to go into the BIOS and enable it. Now we can run 64-bit VMs.

Hope that helps!

-Kevin

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EvilGenius
Contributor
Contributor

I double checked this on all our three machines, "Intel (R) Virtualization Support" (original quote from BIOS) is enabled.

To be sure I downloaded the VMware CPUid utility, it reports the following:

-


Reporting CPUID for 8 logical CPUs...

All CPUs are identical

Family: 06 Model: 0f Stepping: b
ID1ECX ID1EDX ID81ECX ID81EDX
0x0004e3bd 0xbfebfbff 0x00000001 0x20100000

VT is enabled on this CPU bin

Vendor : Intel

Processor Cores : 4

Brand String : Intel(R) Xeon(R) CPU E5345@2,336 GHz

SSE Support : SSE1, SSE2, SSE3, SSSE3

Supports NX / XD : Yes

Supports CMPXCHG16B : Yes

Supports 64-bit Longmode : Yes

Supports 64-bit VMware : Yes

-


So everything should be okay, I assume. VMI support is working fine with 32bit Linux (dmesg says the kernel has recognized and is using vmi support). 64bit systems are running fine, too (both Linux and Windows2k3), but Linux fails booting when activating VMI support for the virtual machine. I tried that with both 64bit Kubuntu 7.10 and CentOS 5, results are the same.

By the way, I tried deactivating VT support in BIOS, the CPUid reports then correctly: "Supports 64-bit VMware: no (may be enabled by BIOS option)".

So is this a bug or am I missing something?

Additional info: motherboard is an INTEL S5000PAL. BIOS is up to date.

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uslacker99
Expert
Expert

There's no 64bit support for VMI.

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rmroz
Contributor
Contributor

Is there any document stating where exactly can you use paravirtualization? It's the first time I got the message stating 64bit paravirt for Linux is not available. 32bit is working fine in my case, while 64bit isn't - just to clarify.

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Texiwill
Leadership
Leadership

Hello,

Check out kernel.org for information on the latest additions to the Linux kernel. If you are looking specifically at one distribution you should check that distributions documentation. But kernel.org is the definitive location for kernel answers.


Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.

CIO Virtualization Blog: http://www.cio.com/blog/index/topic/168354

As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

--
Edward L. Haletky
vExpert XIV: 2009-2023,
VMTN Community Moderator
vSphere Upgrade Saga: https://www.astroarch.com/blogs
GitHub Repo: https://github.com/Texiwill
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