troubleshooting a slow ESX 4

[ArtieZ]

Hello,

I want to know what to check on an ESX server to determine what is causing it to run more slowly than it (reportedly) ran before a power outage. You know how Users are. They associate a major event (like a power failure) with some difference in what they perceive as a User. Even though, the slowness may be caused be something else.

One thing I noticed in /var/log/messages were over 11,000 DHCPREQUEST log entries related to short duration DHCP renewals:

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Sep 22 17:16:04 esxv010 dhclient-uw-104237: DHCPREQUEST on vmk0 to 10.222.1.4 port 67

Sep 22 17:16:04 esxv010 dhclient-uw-104237: DHCPACK from 10.222.1.4

Sep 22 17:16:04 esxv010 dhclient-uw-104237: bound to 10.222.1.200 -- renewal in 247 seconds.

Sep 22 17:20:11 esxv010 dhclient-uw-104237: DHCPREQUEST on vmk0 to 10.222.1.4 port 67

Sep 22 17:20:11 esxv010 dhclient-uw-104237: DHCPACK from 10.222.1.4

Sep 22 17:20:11 esxv010 dhclient-uw-104237: bound to 10.222.1.200 -- renewal in 283 seconds.

Sep 22 17:24:54 esxv010 dhclient-uw-104237: DHCPREQUEST on vmk0 to 10.222.1.4 port 67

Sep 22 17:24:54 esxv010 dhclient-uw-104237: DHCPACK from 10.222.1.4

Sep 22 17:24:54 esxv010 dhclient-uw-104237: bound to 10.222.1.200 -- renewal in 278 seconds.

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How do I determine what this label refers to: dhclient-uw-104237 ?

What could cause the short renewal? Shall I check the DHCP server or is my problem likely on the ESX host? Note that I have other ESX's that do not have eleven thousand DHCP messages dominating the messages log.

Also, I'd be grateful for suggestions on how to investigate the root cause of a slow ESX host.

Cheers!

AZ

[Phokay]

I assume that vmk0 on that particular ESX host is an management port. Can you not assign a static IP on that port as per VMware's best practices? What is the reason that you are using DHCP on the ESX server?

[ArtieZ]

Hi,

Thank you for the specific feedback about vmk0. It seems unlikely that obtaining an IP address from dhcp is the root cause of the slow performance. However I am happy to learn that I am wrong.

It is possible the sysadmin who set up this host is long gone... DHCP was probably used for convenience and never changed to static IP. Is that the problem or merely one particular config that is not consistent with best practices. I'd like to read about the best practice as it relates to vmk0 before I disrupt Users to make changes.

I attempted to research this vmk0 issue but did not yield results. Where are the aforementioned best practices documents that contain these references? Is this interface always called vmk0 or is there another string I could use for searching?

Are there any other suggestions for troubleshooting? Links to docs? blog posts?

Thank you.

Art

[Phokay]

vmk0 is the first vmkernel port created in an ESX(i)4.x servers and it could be used for management or vMotion or FT. You should search for "management interface in ESX" with regards to best practices. But as a matter of fact, any server should have static IP instead of DHCP IP and that is IT industrial best practices. You can have more than one management port on any ESX server. So you create second management port with static IP and make sure all ESX servers and vCenter can ping to that server by new IP address and you can remove the one with DHCP or change the existing vmk0 to static IP and remove the second one.

Changing IP address on ESX(i) server shouldn't affect any VMs running on it. However, if I have HA enabled, then I would be more careful.

[ShekharRana]

You should use static IP for the service console port not the dynamic, This is the recommended setting

[chadwickking]

Hi,

Can be a challenge learning new stuff here are some references to your questions

4.0 best practices I assume you are using vsphere 4.0 andnot 4.1 >

http://www.vmware.com/pdf/Perf_Best_Practices_vSphere4.0.pdf

http://vmetc.com/2009/05/24/vsphere-40-best-practices/

Troubleshooting:

http://communities.vmware.com/servlet/JiveServlet/download/10352-2-28235/vsphere4-performance-troubl...

http://communities.vmware.com/docs/DOC-10352

http://www.virtualinsanity.com/index.php/2010/02/19/performance-troubleshooting-vmware-vsphere-memor...

Going to vmworld site will yield many presentations that are very helpful.

Cheers,

Chad King

VCP-410 | Server+

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