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tji
Contributor
Contributor

Definitive info on Kernel config options for Guest Linux?

I've seen a bunch of questions on various aspects of kernel configuration for a Linux Guest. It seems like this would be a FAQ somewhere. I have searched around but not found it. Am I just missing it? I am primarily looking for the information on an ESX guest.

Some are obvious:

LSI Logic SCSI

Buslogic SCSI

(Intel IDE on VMWare Server)

e1000 Ethernet

AMD Lance Ethernet

But, some things are not as clear.. ACPI/APM to correctly do system shutdown. Timer frequency {1000Hz, 250Hz, 100Hz}, I have read that this can have a big impact on a guest..

Is there an authoritative list somewhere? Or a kernel .config file?

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GBromage
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I don't know of any specific authoritative list. But depending on your kernel version, you'll need to adjust your clock, apic and local apic settings to ensure that the server keeps time correctly.

I hope this information helps you. If it does, please consider awarding points with the 'Helpful' or 'Correct' buttons. If it doesn't help you, please ask for clarification!
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tji
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Thanks for the response. I didn't realize APIC came into play. These things are non-obvious even for experienced Linux people.

This seems so fundamental, I'm really surprised VMware doesn't have a documented set of Linux kernel guidelines.

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Texiwill
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Hello,

THere is a very good book entitled "LINUX Kernel IN a Nutshell" from O'Reilly. Most of the modern kernel options are in there. Otherwise it is like finding a needle in the haystack unless you really like to read kernel code.

Best regards,

Edward L. Haletky, author of the forthcoming 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', publishing January 2008, (c) 2008 Pearson Education. Available on Rough Cuts at http://safari.informit.com/9780132302074

--
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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tji
Contributor
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Actually, it's not an issue of understanding the kernel build, configuration, or even code.. The core issue is understanding the kernel requirements dictated by VMware's virtual hardware.

Some are fairly straightforward -- you just need to know what the devices are virtualized as (e.g. e1000 NIC, LSI Logic SCSI Controller, etc.)

Other issues are more subtle. As was mentioned earlier, some issues about the timers, APIC, etc. are not issues governed by the Linux kernel, but by the VMware environment.

A listing of those issues specific to VMware would help people to more easily configure their systems, and allow users to create Linux systems that functioned better in a VMware environment.

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Texiwill
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Hello,

That list exists, for some Linux OS's, within the forthcoming 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', publishing January 2008, (c) 2008 Pearson Education. Available on Rough Cuts at http://safari.informit.com/9780132302074. For Linux and windows. The virtual hardware is pretty well defined in the documentation from VMware but no laid out in a great way.

Best regards,

Edward

--
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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tji
Contributor
Contributor

This page: http://gentoo-wiki.com/HOWTO_Install_Gentoo_on_VMware

has some good information on kernel configuration parameters. But, it is by no means complete.

When configuring a 2.6.23 kernel for both VMware Server and ESX, I can confirm what they mentioned in the article, the LSI Logic driver did not work in the VM. Once I switched the VM to BusLogic it worked fine.

I used the Intel e1000 driver for ethernet and that works well. (Both the BusLogic and e1000 changes required modifying the vmx file by hand)

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