Yellow Bricks

by Duncan Epping

service console

Check if autostart is enabled from the COS

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I didn’t know this was possible. But you can easily check via the COS if autostarting of VM’s in enabled or not according to this KB article:

  1. Log in as root to your ESX host with SSH.
  2. Open the /etc/vmware/hostd/vmAutoStart.xml file in text editor.
  3. Search for a line that reads:

    <enabled>true</enabled>

  4. If you find the line, the functionality is enabled. If you do not find the line, the functionality is disabled.
  5. If you want to disable autostart for all virtual machines on the host, remove the line.
  6. If you want to enable the functionality, add the line immediately after the line ending with:

    7. <dynamicProperty>

  7. Save your changes and exit.
  8. Restart the management agents on the ESX host:
    service mgmt-vmware restart

Health Check tools I use

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A few days ago Scott Lowe asked me which tools I use to deliver a health check engagement. A health check is a standard VMware PSO engagement, a VMware Consultant will be on site to check the status of your environment and will draw up a report.

I personally use the following tools:

  • Health Check script by A.Mikkelsen → for a quick overview of the current situation and setup, small files and easy to carry around, runs from the Service Console.
  • VMware Health Analyzer Appliance → A linux appliance that can connect to your VC/ESX and analyze log files. At this point in time it’s only available for VMware Employees or Partners with access to Partner Central.
  • Powershell: Report into MS Word → Alan Renouf created this great reporting powershell scripts. It dumps info into a word document. (And i’ve heard he’s also working on a Visio export)
  • Powershell: Health Check Script → Create an html report with datastore, cpu, memory and snapshot info… and more.
  • RVTools → Gives a quick overview of current VM setup like snapshots, memory, cpu etc.
  • Common sense → I hardly encounter really huge problems, mainly decreased availability cause of choices made during implementation / design phase without following VMware’s guidelines. Use common sense is the best advise in this case and read the best practice documents and VMware’s collection of pdf’s!
  • And when there are some disturbing errors in one of the various log files you have the option to run it through one of the many toolkits we internally have.

I’m not using the following tools actively during engagements because of licensing but they can be very usefull in your enviroment:

Create VMFS volumes from the command-line

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I just had to create a couple VMFS volumes from the command-line on a local disk. It’s pretty straight forward but I needed to document it anyway, here it is:

  1. fdisk -l (check what the last partition is)
  2. fdisk /dev/sda
  3. n (new)
  4. default (start block)
  5. default (end block)
  6. t (partition type)
  7. 10 (partition 10, just created)
  8. fb (vmfs type)
  9. w (write config)
  10. reboot (Reboot the host before you format the newly created local partition)
  11. vmkfstools -C vmfs3 /vmfs/devices/disks/vmhba0:0:0:10
  12. Go to VI Client, Refresh storage view and rename the newly created volume
You can align the VMFS volume as follows, before you do step 9:
  1. X
  2. b
  3. 1
  4. 128 (disk alignment, check your SAN manual for the correct value, 128 is correct in most cases…)
  5. W

ESXi and warranty

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I just finished my VIMA blog and 12 hours later Edward published an article on security and warranty when opening up ESXi for SSH access:

Working with VMware ESXi can be frustrating; you’re not supposed to enable the Dropbear SSH client or use its technical support mode without the assistance of a VMware support representative. System administrators, however, may be tempted to use tech support mode (or enable Dropbear) to fix problems or manage connections on the fly. Cracking this security shell, however, can void the VMware ESXi warranty and break support contracts.

Read the complete article here!

And Edward is right. The consultants and sys admins are used to SSH access to their ESX boxes and most of them opened up Dropbear SSH on their ESXi box as soon as they heard it was possible. That’s why I think everyone should start investigating VIMA. When I got some more time on my hands I will try to post more on VIMA.

VMotioning your Service Console?!

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Some of you might have looked into VIMA already. Those of you that didn’t please check it out because I expect this to be the way that VMware is heading. Note, I don’t know if it really is the way VMware is heading, but a Service Console with VMotion capabilities sounds like a winner to me. A little birdie also just told me that APC, the UPS Company, is finishing their VIMA Compatible UPS software agent!

The cool thing about VIMA is that it includes the RCLI commands, the Perl toolkit and a logger daemon named vilogd. The last one will be the topic for this blog. So what does this logger daemon include?
The vilogd daemon collects all the logs that are available through the DiagnosticManager VI API:

  • ESX/ESXi3.x service log
  • VI Client Agent log
  • Virtual Machine kernel core file
  • System log

First add servers to the VIMA appliance:

sudo vifp addserver esx01.localdomain
sudo vifp addserver esx02.localdomain

Now you will need to enable the vilogd for the servers you added:

vilogger enable

So when you’ve enabled it you could also set the max log size(default 5MB) or for instance the amount of log rotations(default 5 rotations). So the way you do this is as follows:

vilogger updatepolicy --maxfilesize 10 --collectionperiod 5 --numrotation 10

So the maximum filesize of a log will be 10MB. When the 10MB has been reached it will rotate the log files, their will be 10 log files kept by setting “numrotation”. The log files will be collected every 5 seconds.

As you can see, it’s kinda like a syslog daemon but in my opinion a bit easier to setup. I would love to see a web interface of some sort that immediately points you out to possible problems, and with a bit of work it should also be possible to direct people to kb articles on these problems. But we will just have to wait and see what will be coming up. I honostly don’t know.