VM's Mysterious Brief Disconnects

[dhayashi]

Hi,

I'm having a strange problem where I have two hosts in a cluster and on two seperate days, they suddenly disconnect their vms and reconnect over a span of 5 secs.

On another note : I also notice that when I use the VI client and connected to the hosts individually, their event logs were empty. On the VC, I see the events for these hosts.

Also my other cluster on two other different hosts with a similar setup shows their individual event logs just fine.

Should there be a reason for concern since this happen so quickly and only occured once on each host in question so far?

Thank you,

Sincerely,

dhayashi

[Lightbulb]

Is it that the VMs and ESX hosts are disconnected from network for 5 sec interval?

If so check the physical switch/switchport for signs of issues.

If the Hosts are disconnected from VC server for short period of time check /var/log/vmkernel, /var/log/vmware//hostd.log and /var/log/vmware/vpx/vpxa.log for errors.

If I have misunderstood your request I apologize.

[Chamon]

What type of physical switch are you using? We had a dev cluster connected to a Netgear switch and saw this all the time. Replaced it with an old Cisco switch and it went away.

[dhayashi]

We're using Cisco 3750s so hopefully it is not a switch issue. I'll try to ask the network folks about the logs during the time frame being affected.

Thank you,

dhayashi

[dhayashi]

it's actually the vm disconnecting in this case, not the host. So considering we're using a SAN, it could be network related.

[Chamon]

Ar you using iSCSI or FC

[dhayashi]

iSCSI

[Chamon]

Have you checked your VMkernel Portgroup settings?

Did you find any errors or warnings in the logs mentioned above?

Message was edited by: Chamon