Breaking news:
As of the first of July I will start as a PSO Consultant at VMware! I’m very happy that VMware provided me with this opportunity. I want to thank Ictivity BV for understanding my decision and making this transition possible and easy. So the next couple of weeks I will be extremely busy finishing my house and finishing projects and transferring accounts/customers to colleagues.
VMware
Good read: how many vm’s on 1 ESX host
Check out this topic on the VMTN forum by Gabrie. It’s a good read about how many vm’s one would dare to run on an ESX host.
TexiWill:
This really depends. I know companies that are doing no more than a 10:1 or 20:1 compression, but there are other companies with 50+ VMs running on one box (at the time it was a DL760 with 8 CPUs and 64GBs of memory. I do know that the max vCPUs you can put on a system is still 8 * pCores and the larget box I have seen is the DL580G4 with 4 quad cores (16 cores) and 512GBs of memory….. So maximally 128 vCPUs…..
Ken.Cline:
I make this decision based on a couple things:* – How important are the VMs in questions?
* If they’re truly “mission critical”, then I keep the number small – on the order of 10:1
* If they’re “important”, then let’s look at 20:1
* If they’re “who cares if they’re up”, then load ’em up!* – How large is the environment? I like to deploy a minimum of two hosts (three makes me happier)
* 20 systems @ 2 hosts = 10:1, @ 3 hosts = 7:1
* 100 systems @ 2 hosts = I wouldn’t do it, @ 3 hosts = 34:1
* 1,000 systems – now you’re talking! @ 20 hosts = 50:1, @ 30 hosts = 34:1, @ 20 hosts = 50:1, @ 10 hosts = 100:1
* 10,000 systems – you can bet I’m going to have a few hosts with 50 to 60 (or more) VMs and some hosts with 10 (or less) VMs!So, there’s not single “right” answer (other than “it depends”)
VC 2.5 HA constraints
VMTN user “ian4563” recently posted a thread about problems with the HA constraints. The error that was pulled from the log files:
Das admission check failed. Configured failover: 2, Expected new failover: 0
And the solution according to VMTN user “eziskind”, who also is a VMware employee:
Looks like you have some 4-cpu vms in the clusters too. That will really skew things. You’re being hit by the combination of 2 new things in the HA admission control for VC 2.5:
1) If no reservation is set for a vm (or it is set to 0), use default of 256MHz, 256MB. (these values can be changed using HA advanced options: das.vmMemoryMinMB, das.vmCpuMinMHz)
2) For the cpu component of the slot, use (max MHz per virtual cpu) * (max number of vcpu’s per vm)The HA admission control algorithm is overly conservative in non-homogenous clusters, ie. ones with vms which have different reservations and/or vcpu number. #2 above makes it more conservative. Given these limitations, its best to try to keep the cluster as homogenous as possible. Is it possible to put the 4-cpu vms in a separate cluster? If not, you can try setting the default vm resources to 0 (using the advanced options in #1). This is how things worked in VC 2.0.
Thanks goes out to my colleague Remco for pointing this topic out.
Site Recovery Manager, random thoughts
I’ve been disconnected from the internet the last couple of days because of a UPC screw up. So I missed out on all the SRM blogging. I am just reading all the new blogs that were created over the last couple of days. Here are just a couple random thoughts…
- The SRM docs talk about a “proteced” and a “recovery” site. Does this mean that SRM always needs an “active/passive” setup. In other words, can I only use 1 SAN for production.
Why? Well I could imagine that one would benefit from having some sort of load balancing with 2 VirtualDatacenters and 2 active SAN’s. Not only will the uptime increase, because if a site fails only half will failover, but also performance will be less of an issue having half of your active vm’s running on another SAN and cluster. And I’m not even gonna talk about TCO when half of your environment is doing nothing. - What about the VirtualCenter licensing? Do I need 2 VirtualCenter Licenses?
- What about failing back? I played around with a beta and there’s no automated option for a fail back at this moment, when will it be available?
- What about a third site? Think about switching datacenters every week or so for the insurance / banking industry. (Think Anti-Terrorism.)
VMware tools version?
A couple of weeks ago I contacted Rob, the man behind RVTools, and asked him if he could add an export or copy+past functionality to his amazing tool “RVTools”. This amazing tool checks the VMware tools version and gives you the option to update them all at once. Rob updated his tool today:
Version 1.1
Changes: May 10, 2008
You can copy the selected datagrid values with ctrl-c to the clipboard. The header text is automatically included. After this you can paste the clipboard data to your favorite editor.
The login form remembers the names and/or IP addresses of the entered ESX hosts and/or VirtualCenter servers.
You can use a filter to display only the “templates” or “virtual machines”.
Annotations “notes” field is visible in the datagrid.
http://rvtools.deveij.com
Especially the copy and paste option is handy for those who do consultancy like me, thanks Rob for adding this feature and for this excellent tool! Nextup converting it into a VirtualCenter plugin?!? 😉