Yellow Bricks

by Duncan Epping

esxi

Train Signal

· ·

Almost a year ago I wrote an article on a CBT by Train Signal. I really enjoyed watching the CBT and that says a lot coming from someone that never used to be a CBT fan. In the end the ease of learning when and wherever you want is what convinced me. Another reason to use a CBT instead of a classroom training is costs, which is most definitely a valid reason in these times of financial crisis.

If you’re not familiar with CBT’s check out this example:

I managed to get a discount for my readers, buy one of the virtualization related(VMware ESX, Server, Workstation etc) CBT’s and get a 25% reduction! All you need to do is head over to Train Signal and enter the following coupon code “YELLOWBRICKS”. And by buying a CBT you also support Yellow-Bricks.com!

“Quick” Migration for VM’s running on ESXi 3.5u2+

· ·

Mike D was the first one that actually wrote a powershell quick migration script that exactly does the same as Microsofts Quick Migration. (Suspend on host 1, Resume on host 2.) Yesterday William Lam emailed me about a script that he created that actually does the same as Mike D’s script. But, William’s script was specifically designed for ESXi and he used Perl to do the job. Before we get into the “is this supported with the current API/RCLI discussion“, William contacted VMware and certain procedures used will be restricted again in the next update for ESXi.

William described his script as follows:

ESXi is a formidable hypervisor solution in both licensed and free operation mode. When fully licensed in a Virtual Center cluster, ESXi’s features (VMotion, HA, DRS, VCB, etc…) are indistinguishable from ESX. One feature of importance, VMotion, is used to perform live migrations of VMs that reside on shared storage from one host to another. In free operation mode however, ESXi hosts are independent of each other, in which case, useful features like VMotion become unusable.

The motivation for this script (ghettoQuickMigrate.sh) then is to provide administrators running the free version of ESXi on several hosts with the capability to perform Hyper-V-like “quick” migrations of virtual machines residing on shared storage between the hosts. VMware’s VIMA virtual appliance was chosen as the central launch point for the quick migration process. ghettoQuickMigration.sh is executed from within VIMA and is compatible with ESXi 3.5u2+.

William wrote an extensive Communities blog post on how this script works, what the requirements are and how to set this up. Another reason for you to start using VIMA!

High Availability “Deepdive” page

· ·

I’ve just created a new Page. This page will also deal about VMware HA. I threw all my “deepdive” posts into one page which makes it easier to find for you guys and search engines. But most important, easier to maintain. When I’ve got more technical in-depth information I will add it to the page.

Check it out and let me know what you think.

vimsh, what can I do with it?

· ·

Vimsh(and vmware-vim-cm) is probably one of the worst documented commands out there. At the same time it’s one of the most powerful commands(I know it’s a shell…) out there. You name it and “vimsh” does it. Most of you ran into the “enabling vmotion” from the Service Console problem when first starting out with scripted install. Vimsh solves this:

/usr/bin/vmware-vim-cmd “hostsvc/vmotion/vnic_set vmk0″

As you can see “vimsh” is very powerful, but most of the other command-line stuff can be handled with the “esxcfg-*” commands. Well almost, for instance we talked about enabling autostart in my previous post. According to the KB article you must edit the file “/etc/vmware/hostd/vmAutoStart.xml”. Editing this file can be dangerous, I guess this goes for most ESX configuration files. During the Dutch VMUG I had a short chat with Wil van Antwerpen, Wil told me he was busy documenting the “vimsh” “command” in a wiki. After I published the enabling autostart blog Wil emailed me that this could and should be done with “vimsh”. I fully agree with Wil:

vmware-vim-cmd /hostsvc/autostartmanager/enable_autostart true

This enables the autostart functionality without manually editing the files. But I guess you would like to check if it’s enabled or disabled:

vmware-vim-cmd /hostsvc/autostartmanager/get_defaults

The big question remains, how do I know what I can and can’t do with “vimsh”. Well that’s the main reason for this post, as I said Wil has been very busy documenting “vimsh”. Wil created VI-Toolkit.com. VI-Toolkit.com contains a section on vimsh. Besides the the info that the vimsh command provices Wil added sample code. The sample code can be very usefull, but the search function is even more useful. Searching the vimsh documentation provides you with a fast way to check if a specific configuration action can be scripted with “vimsh”. For instance a search on “vimsh role” returns the following:

* Vimsvc/auth/role add
==== vimsh vimsvc/auth/role_add ==== Usage: role_add roleName [priv0] [priv1] [priv2] [priv3] [priv4]
171 B (24 words) – 14:32, 26 December 2008
* Vimsvc/auth/role permissions
==== vimsh vimsvc/auth/role_permissions ==== Usage: role_permissions roleName
1 KB (118 words) – 22:26, 28 December 2008
* Vimsvc/auth/role remove
==== vimsh vimsvc/auth/role_remove ==== Usage: role_remove roleName [failIfUsed]
123 B (16 words) – 14:34, 26 December 2008
* Vimsvc/auth/roles
==== vimsh vimsvc/auth/roles ==== Usage: roles
7 KB (550 words) – 21:50, 28 December 2008

I guess I can sum up this blog post in just one line:”Bookmark VI-Toolkit.com and add it to your RSS reader!”. Be sure to not miss out on anything regarding “vimsh” or any of the VI Toolkits that Wil be be describing and aggregating source code for. The “vimsh” section alone is already 345 pages large and it will continue to grow even more. Keep up the great work Wil and it was nice meeting you in person!

Heap size VMFS3

· ·

I was talking to a fellow consultant today. He ran into the following error messages at one of his customer sites:

vmkernel: 8:18:59:58.640 cpu2:1410)WARNING: Heap: 1370: Heap_Align(vmfs3, 4096/4096 bytes, 4 align) failed. caller: 0x8fdbd0
vmkernel: 8:18:59:58.640 cpu2:1410)WARNING: Heap: 1266: Heap vmfs3: Maximum allowed growth (24) too small for size (8192)

During the conversation I knew I’d seen this problem before. But the problem that I witnessed was related to a high threshold value in Vizioncore vFoglight. I knew it was possible to change the setting:

  1. Open vCenter, and click a specific host
  2. Click on the “Configurations” tab
  3. Click on Advanced Settings, VMFS3
  4. Change the value of “VMFS3.MaxHeapSizeMB”

The default value is 16MB, this allows for a maximum of 4TB of open vmdk’s on a single host. The max setting is 128MB which allows for a maximum of 32TB of open vmdk’s on a single host. Keep this in mind when designing your environment.

Keep in mind that this is ESX 3.5 only, you can’t change the heap size in ESX 3.0.x.