Comments on: HA best practices http://www.yellow-bricks.com/2008/10/27/ha-best-practices/ Building blocks for virtualization... Fri, 19 Mar 2010 21:53:34 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: justme http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1628 justme Tue, 11 Nov 2008 03:31:01 +0000 http://www.yellow-bricks.com/?p=737#comment-1628 @ Jay - If the host looses all network access, how do you plan to login and cleanly shut the guests down? If you loose all redundancy on your service console, you most likely loose it on your virtual machine networks as well. Without powering them down, you will have file locks which means you can't restart them on other hosts. @ Jay – If the host looses all network access, how do you plan to login and cleanly shut the guests down? If you loose all redundancy on your service console, you most likely loose it on your virtual machine networks as well.

Without powering them down, you will have file locks which means you can’t restart them on other hosts.

]]> By: Duncan Epping http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1509 Duncan Epping Thu, 30 Oct 2008 14:26:57 +0000 http://www.yellow-bricks.com/?p=737#comment-1509 No that's not necessary anymore. HA will get the ip+hostnames from VC and cache this info in FT_HOSTS! So no need to do manual hosts files anymore! No that’s not necessary anymore. HA will get the ip+hostnames from VC and cache this info in FT_HOSTS! So no need to do manual hosts files anymore!

]]> By: Fred http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1506 Fred Thu, 30 Oct 2008 08:48:26 +0000 http://www.yellow-bricks.com/?p=737#comment-1506 Hello, "Well as of 3.5 U2 HA doesn’t rely on host files or dns anymore but get’s its name resolving information from VirtualCenter." So what about a virtual machine VCenter ? If the VM is stopped by HA, does it means that the name resolution will not work ? I use to fill the /etc/hosts on each esx 3.5 U2, is it the righ way to configure properly HA ? Thanks for your answer ! Hello,
“Well as of 3.5 U2 HA doesn’t rely on host files or dns anymore but get’s its name resolving information from VirtualCenter.”
So what about a virtual machine VCenter ? If the VM is stopped by HA, does it means that the name resolution will not work ?
I use to fill the /etc/hosts on each esx 3.5 U2, is it the righ way to configure properly HA ?
Thanks for your answer !

]]> By: Duncan Epping http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1470 Duncan Epping Mon, 27 Oct 2008 14:04:31 +0000 http://www.yellow-bricks.com/?p=737#comment-1470 Well, I don't like to use a server that's degraded in any way. If you know what you are doing and have a valid argument to leave them powered on, go ahead. But then you should be monitoring your system 24x7 in my opinion, or at least trigger an action at host degradation... Would be nice though if you could have a "heartbeat" only network on your VM vSwitch, this way you'll know if you need to switch over in case of an isolation or not. Well, I don’t like to use a server that’s degraded in any way. If you know what you are doing and have a valid argument to leave them powered on, go ahead. But then you should be monitoring your system 24×7 in my opinion, or at least trigger an action at host degradation…

Would be nice though if you could have a “heartbeat” only network on your VM vSwitch, this way you’ll know if you need to switch over in case of an isolation or not.

]]> By: Jay http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1469 Jay Mon, 27 Oct 2008 13:58:11 +0000 http://www.yellow-bricks.com/?p=737#comment-1469 is there any reason why to chose following? “Change default isolation response to “power off vm” and set restart priorities for your AD/DNS/VC/SQL servers Change default isolation response to “power off vm” and set restart priorities for your AD/DNS/VC/SQL servers ” I think leaving all VMs power on is a better idea because all VM’s then can be scheduled to come down and bought up gracefully on different hosts. Above would just powered off the VMs and will not shutdown servers gracefully this could be a potential problem with DB servers. Troubleshooting can also be done on isolated host to see if isolated host can be fixed before shutting down VMs. is there any reason why to chose following?

“Change default isolation response to “power off vm” and set restart priorities for your AD/DNS/VC/SQL servers Change default isolation response to “power off vm” and set restart priorities for your AD/DNS/VC/SQL servers ”

I think leaving all VMs power on is a better idea because all VM’s then can be scheduled to come down and bought up gracefully on different hosts. Above would just powered off the VMs and will not shutdown servers gracefully this could be a potential problem with DB servers. Troubleshooting can also be done on isolated host to see if isolated host can be fixed before shutting down VMs.

]]> By: Duncan Epping http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1467 Duncan Epping Mon, 27 Oct 2008 13:45:58 +0000 http://www.yellow-bricks.com/?p=737#comment-1467 Well as of 3.5 U2 HA doesn't rely on host files or dns anymore but get's its name resolving information from VirtualCenter. Well as of 3.5 U2 HA doesn’t rely on host files or dns anymore but get’s its name resolving information from VirtualCenter.

]]> By: Thomas Weyell http://www.yellow-bricks.com/2008/10/27/ha-best-practices/comment-page-1/#comment-1466 Thomas Weyell Mon, 27 Oct 2008 13:40:17 +0000 http://www.yellow-bricks.com/?p=737#comment-1466 Hi, I tell my customers that they must foster there hosts files. Thomas Hi,

I tell my customers that they must foster there hosts files.

Thomas

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