Within Reason comments

"VMware HA?" by Ian Fletcher

Mon, 06 Jul 2009 13:00:22 +0000

Hi Ceri, Just come across your comments regards VMware HA and I thought that I'd just explain that HA was designed to be a way of quickly restarting Virtual Machine in the event of the sudden loss of and ESX server (power, hardware etc.) In addition it offers the option to force the power off of virtual machines in the event of an ESX server becoming isolated on the heartbeat network from the other ESX servers in the cluster. This is where you're certain that loss of connectivity on the heartbeat network will also result in loss of connectivity for VMs on the VM network. The other option is to leave VMs running and assume that the loss is just of the heartbeat network. Hence the need to have resilience for the service console network to avoid isolation of an ESX server causing what in effect would be a "false positive" for ESX isolation. To protect the VM network you should be looking at NIC teaming and for the storage ensuring that you have multi-pathing. HA isn't designed to help you with those network and storage problems. HA is all about restarting VMs in the event of an ESX failure and also some options in the event of an ESX server being isolated - dependant on the physical equipment being used for the service console and VM networks.

"Doubts Even Here: the point of disbelief" by Michael Janke

Sun, 31 May 2009 01:12:09 +0000

Ceri - Thanks for the de-hyping. It's a good read. ;) --Mike

"VMware HA?" by Ceri Davies

Sat, 30 May 2009 19:19:51 +0000

@majinbo, That's a reasonable idea but unfortunately would cause VMware HA to become even less likely to fail given a network failure.

Setting the filer IP as the only isolation address (setting das.usedefaultisolationaddress false and das.isolationaddress to the filer's IP) wold protect from filer loss, but not from service console loss and of course does nothing for Fiber Channel users.

I think that the best mitigation I can currently manage is to put the Service Console on the same physical interfaces as the Virtual Machine networks so that a failure of either will cause a failover.

As for FC failure, compounded with the complete lack of mirroring, we're just SOL.

"VMware HA?" by majinboo

Mon, 25 May 2009 10:34:36 +0000

I think that you could improve the reliability by modifying your setup : - use the das.isolationaddress parameter, you can provide a second address by using das.isolationadress2. You can put any IP address that responds to ICMP ping requests. So in you setup, you may use gateway's IP and your filer's IP. - configure the isolation response in virtualcenter If you haven't read it, I suggest you to read this WhitePaper : http://www.vmware.com/resources/techresources/402 . This a good starting point on the subject.

"Check your T5220!" by Alicia

Sun, 17 Feb 2008 08:11:21 +0000

Im waiting for a more improved version to come out. I dont care how long the wait, because this series kinda sucks to be honest.

"OpenSolaris as SCSI target" by Ceri

Tue, 11 Dec 2007 22:03:06 +0000

Hi Ceri, Yes, it's a little weird :) These are not my binaries, they're the ones provided by the COMSTAR project and yes, they do work on Solaris 10. Specifically, it's Solaris 10 update 3 with a reasonable number of patches. I'm not sure what compiler the COMSTAR team used, but these ones definitely work. PS I've emailed this response as well.

"OpenSolaris as SCSI target" by CeriDavies@Hotmail.com

Tue, 11 Dec 2007 21:34:53 +0000

Hi, my name is Ceri (Ifor) Davies, I am writing a qlogic target mode driver for solaris 10, and am thinking of switching to Comstar. Are you recompiling for solaris 10, or are you saying your nevada binaries worked with solaris 10? That would surprise me, since nevada uses stdio 11 (I think). The qlogic qlc driver panics on solaris 10 if compiled with studio 11, and has to be compiled with studio 10. P.S. Your having the same name is weird

"message overflow on /dev/log minor #5 -- is syslogd(1M) running?" by joeli

Mon, 10 Sep 2007 14:11:28 +0000

Me says thank you too! ;)

"NetBeans on FreeBSD" by Ceri Davies

Tue, 04 Sep 2007 09:38:26 +0000

Hi Amit, I hadn't; do you mean the milestones, eg http://dlc.sun.com/netbeans/download/6.0/milestones/latest/ ?
Not sure why you can't just provide FreeBSD builds to be honest ;-)

"NetBeans on FreeBSD" by Amit

Mon, 03 Sep 2007 09:47:46 +0000

Hi! I am Amit, NetBeans Community Docs co-ordinator. Did you try NetBeans 6 development builds on FeeBSD? If you have not why dont you try it out and may be contribute a small write up to the NetBeans Community Docs. Looking forward to see your contribution. Thanks Amit