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14 Replies Last post: Mar 25, 2008 3:22 PM by mvaughn25  

VM dissapears for 30 sec during vmotion posted: Dec 17, 2007 11:43 AM

Click to view mvaughn25's profile Novice vExpert 19 posts since
Aug 17, 2006
I recently rebuilt my lab servers to with ESX 3.5. Since then, I have noticed a weird "hiccup" during the VMotion process. VMotion works and does not record any errors, but the VM will stop responding to pings for about 20-30 seconds in the middle of the process. Has anyone else seen this? Have I missed something in rebuilding my ESX servers, maybe a network setting? Prior to this, I never experienced more than one dropped ping, and it always recovered immediately for no noticable downtime.

Re: VM dissapears for 30 sec during vmotion

1. Dec 17, 2007 12:05 PM in response to: mvaughn25
Click to view uslacker99's profile Expert 275 posts since
Sep 26, 2005
Can you do a ping from the VM and see if you lose any connectivity? How many NICs do you have in the VSwitch that the VM is on?

Re: VM dissapears for 30 sec during vmotion

3. Dec 17, 2007 4:46 PM in response to: mvaughn25
Click to view uslacker99's profile Expert 275 posts since
Sep 26, 2005
Hard to say what the problem is. Any errors/warnings in /var/log/vmkernel?

Re: VM dissapears for 30 sec during vmotion

5. Dec 23, 2007 1:40 AM in response to: mvaughn25
Click to view Rumple's profile Master 1,398 posts since
Jan 6, 2005

The step that typically causes drops is the MAC address being swapped from esx server to esx server. I believe this causes a few seconds where the same mac address shows up on 2 different ports. If you do not have portfast enabled on the gear (if its cisco), that will cause that 30 second delay. Other managed switches also have settings that allow that MAc to swap places really quickly as well but I can't provide much more information then that.

If you can ping out from the vm and drop a packet but from outside into the VM tells me that it could also be a reverse arp issue. The workstation is still sending the information to the wrong port because the switch hasn't realized the mac is now on a different port until it does its refresh of arp tables...


Re: VM dissapears for 30 sec during vmotion

6. Dec 23, 2007 2:29 AM in response to: Rumple
Click to view depping's profile Champion VMware Employees User Moderators 3,205 posts since
Jan 17, 2005
Rumple is right, enable portfast disable spanning tree on these ports. Will probably solve this problem, there are numerous pdf's about this subject.

Duncan
http://www.ictivity.nl

Re: VM dissapears for 30 sec during vmotion

8. Dec 24, 2007 3:16 AM in response to: mvaughn25
Click to view tom howarth's profile Guru User Moderators vExpert 7,454 posts since
Jul 25, 2005
Please remember to award points for those helpful or correct answers.

Tom Howarth
VMware Communities User Moderator

Re: VM dissapears for 30 sec during vmotion

10. Jan 25, 2008 8:32 AM in response to: mvaughn25
Click to view jccoca's profile Hot Shot 167 posts since
May 5, 2004
Disable port-security in the cisco switch for the VM ports.

Re: VM dissapears for 30 sec during vmotion

11. Jan 25, 2008 11:52 AM in response to: mvaughn25
Click to view BORGcube's profile Novice VMware Employees 13 posts since
Apr 28, 2004
If the VM dissapears (sic) for 30 seconds it sounds very much like Spanning tree. Make sure you have spanning tree port fast enabled on all your network links attached to your ESX Server.

Re: VM dissapears for 30 sec during vmotion

12. Mar 25, 2008 2:57 PM in response to: mvaughn25
Click to view vvarnell's profile Enthusiast 107 posts since
Jan 11, 2005

I'm seeing this (or something similar) as well, but it is between 16 and 20 seconds (4-5 dropped pings).

My cluster is 16 nodes, eleven ESX 3.0.2 and five ESX 3.5. I noticed this in the process of upgrading to ESX 3.5.

Vmotion behavior:

  • 3.5 to 3.5 -> 4-5 dropped pings
  • 3.0.2 to 3.5 -> 4-6 dropped pings
  • 3.0.2 to 3.0.2 -> 1 dropped ping (this has been the case since 2.5 and what I consider "normal")
  • 3.5 to 3.0.2 -> 2-3 dropped pings

Also, the startup of the vMotion seems to take several seconds longer than previously.

Only changes are the upgrades to ESX 3.5 (done with CD-based upgrade, ZIP-based upgrade and new non-upgrade methods). No SAN or network changes and the timing is wrong for spanning tree/portfast.

Thoughts? Ideas?

VwV

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