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Network timeouts for VM guests

This is SO weird. That SQL timeout issue was caused by network timeouts, and it disappeared when we moved the SQL server to another ESX host. However, the issue re-appeared, this time on the host with the vCenter guests...

Further analysis reveals this interesting tidbit:

29/06/2009 12:08:29 PM -- Reply from bytes=32 time<1ms ttl="">
29/06/2009 12:08:34 PM -- Request timed out.
29/06/2009 12:09:24 PM -- Request timed out.
29/06/2009 12:09:26 PM -- Reply from bytes=32 time=1028ms TTL=128

29/06/2009 12:38:29 PM -- Reply from bytes=32 time<1ms ttl="">
29/06/2009 12:38:35 PM -- Request timed out.
29/06/2009 12:39:24 PM -- Request timed out.
29/06/2009 12:39:27 PM -- Reply from bytes=32 time=1445ms TTL=128

29/06/2009 1:08:14 PM -- Reply from bytes=32 time<1ms ttl="">
29/06/2009 1:08:20 PM -- Request timed out.
29/06/2009 1:09:09 PM -- Request timed out.
29/06/2009 1:09:12 PM -- Reply from bytes=32 time=1772ms TTL=128

29/06/2009 1:38:27 PM -- Reply from bytes=32 time<1ms ttl="">
29/06/2009 1:38:33 PM -- Request timed out.
29/06/2009 1:39:22 PM -- Request timed out.
29/06/2009 1:39:26 PM -- Reply from bytes=32 time=2554ms TTL=128

29/06/2009 2:08:23 PM -- Reply from bytes=32 time<1ms ttl="">
29/06/2009 2:08:28 PM -- Request timed out.
29/06/2009 2:09:19 PM -- Request timed out.
29/06/2009 2:09:22 PM -- Reply from bytes=32 time=1921ms TTL=128

29/06/2009 2:38:29 PM -- Reply from bytes=32 time<1ms ttl="">
29/06/2009 2:38:34 PM -- Request timed out.
29/06/2009 2:39:23 PM -- Request timed out.
29/06/2009 2:39:28 PM -- Reply from bytes=32 time=3497ms TTL=128

(it continues)

So every 30 minutes there is a network outage of a minute or so on those guests. You'd say, 'hmm, hardware? cabling?', but NAY! Host pings reveal no timeouts, and other guests on the same host do not have the same timeouts. How weird is that???

Dan suggested that maybe the OS was coming into play, but when the problem initially occurred, there were a mix of 2008 and 2003 clients affected.

I'm going to run a Wireshark session on the LAN switch they are using, see if that comes up with something.

Update: The wireshark session hasn't really added too much to the proverbial pot here, especially since I can't figure out how to get a time range filtered out. Frame.time "" to frame.time "" doesn't seem to work.

Oh well, other issues to deal with for now.


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