The greatest challenge to any thinker is stating the problem in a way that will allow a solution

Bertrand Russell

Welcome to vBlog, a personal record of my techy tinkerings and particular ponderings.

I tend to focus on VMware virtualisation, and the interaction/automation of it using PowerCLI (VMware's PowerShell Snapin), but anything that I happen to stumble across that seems like it might be of use at a later date, may well get recorded here.

I also maintain vWiki, which was a predecessor to this blog. Wiki's are great for quickly recording snippets of info, but tend not to look that great; Blog's are better looking things, but seem to require more effort so that the posts/articles are accessible in their own right. As a result I tend to update both interchangeably as available time, and depth of thought, permit.

If you happen to find anything of use, or in need of correction please leave a comment. Knowing that my ramblings are of some use is a great reward; and similarly I'd hate to waste anybody's time by feeding them duff info.

See these pages for me info about me, and my vBlog, and below for my recent posts...

15 Nov 2012

VMware

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Whilst I’ve worked on VMware products (predominantly ESX and VI/vSphere) for many years now (since 2006-ish). I’ve only been a member of the UK VM User Group (VMUG) for a few months. And today I ventured to the VMware User Group Conference.

I was apprehensive at going for two reasons… Continue reading →

3 Apr 2012

VMware

5 comments

With SSH access to your ESX servers, it is relatively easy to get the driver and firmware software revision versions that are running (see further reading section at bottom of post).  Which is fine for a one-off inspection, but if you want review your entire ESX estate, this can be quite tedious.

With the wonder of PowerCLI, it is possible to gain most of this information from your vCentre, which will have sourced the information from your ESX through its hardware CIM provider.  But the quality of data returned in this manner varies, you can get…

  • No data (if you server vendor hasn’t fully implemented CIM to cover the server and peripheral devices, or you haven’t installed the CIM provider software, even if you can get data for X and Y, Z may be missing, for example HBA firmware on all HP servers I’ve had the pleasure of looking after)
  • Duplicate data (if you’ve upgraded software you can sometimes get both old and new versions reported)
  • Inconsistent data (representations vary between manufacturers/vendors, so dealing with different makes or even models from the same manufacturer is problematic)

I do all reporting through PowerShell and PowerCLI scripts, and had got fed up with having to tinker with my scripts to try and never fully trusting the data I was seeing.  But more recently I’ve been using PowerShell to act as an SSH client, so decided to take a different approach…
Continue reading →

12 Mar 2012

VMware

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Whilst not always recommended for production use, its certainly very common for admins to want to have SSH access enabled to all ESX’s all of the time. You don’t need it for day to day support tasks, but it can be very useful, especially when things start to go wrong.  And to my mind, the easier it is to start getting into the detail of an incident, all the better chances you have of resolving it quickly and correctly.

However, enabling SSH access causes a yellow warning on your ESX’s with is annoying, and risks clouding other more important errors you might want to take action on.

If you’re running ESX5 you may see…

  • ESXi Shell for the Host has been enabled
  • SSH for the host has been enabled

There are three ways that I’m aware of to remove the warning… Continue reading →

Upgrading VMTools always seems like such an afterthought.  You get through the effort of upgrading your vCentre, and ESX’s without any service interruption, then are left with a load of VM’s with out-of-date Tools and little authority to take them down as part of the upgrade.  Plus if you’re faced with the drudgery of having to speak to all sorts of different people and departments, its the kind of task that is only ever on the back-burner.

I tend to try to upgrade machines during ad-hoc reboots, which isn’t always sensible (during an service incident for example), and requires you to remember (not always possible if you’ve been up most of the night due to young kids / over exuberant drinkage).

There is an often overlooked option that lets you automatically update VM’s during a bounce, the only problem is – how to set on all your VM’s and retain full use of your mouse wielding arm and eyes…? Continue reading →

Recently I had to migrate a collection of virtual machines from one vCentre to another.  They didn’t have to change datastore, so there was no need to whip VMware Converter out and cause a mass movement of data.  Just a case of unregistering from one vCentre and registering with another.  However, there were over 20 machines, in various datastores hosting some VM’s with duplicate VM names, meaning it would be quite a laborious process, and manual error prone.

So, in order to make the process nice and reliable and avoid any machines getting lost on the way, I wrote a quick script to do the hard work… Continue reading →

vApps can be wonderful things.  Essentially resource pools on steroids, I never really used resource pools that much (unless I was revising for a VCP exam), but I find the ability to control a bunch of VM’s as one entity, controlling their start-up and shut-down order very useful.  However, controlling that start-up and shut-down functionality is a pain.  The default options are (for me) wrong, and its a laborious task to go through them all and update.

As soon as I feel the potential for RSI in my mouse arm, is when I feel the need for a bit of PowerCLI script-o-magic… Continue reading →

The memory sticks in HP blades (as in any server) will occasionally experience errors, more often than not these are recoverable, and are handled without pulling down the software that’s running on it.  However, a tally is kept, so that poorly memory stick can be identified and dealt with.

Non-critical (recoverable) memory errors that have breached an acceptable level generate an error through to the HP Onboard Administrator (OA) as a degraded memory state.  This will be visible as a yellow warning triangle on the OA, will propagate through to your monitoring system (eg SCOM), and through the vCentre Hardware Status for the affected ESX.

Once the problematic memory stick is swapped out, the alert will clear from the OA (and SCOM), but will still be visible through vCentre.  In order to clear down, the server’s System Event Log needs to be reset, and this refreshed through the CIM provider… Continue reading →

I always found being able to copy and paste between your desktop machine and a VM through the VI Client a godsend.  In the good old days this was always enabled by default, so you could copy and paste text between your desktop and VM consoles to your heart’s content.

Since ESX 4.1, its been disabled by default in order to provide a more secure, locked down environment out of the box.  There are two main options if you enjoyed the old-skool benefits; use a different app, or just re-enable the old functionality… Continue reading →

Came across an odd problem today, whereby nobody could use any of the deploy template options as they were all greyed out…

  • Clone…
  • Convert to Virtual Machine…
  • Deploy Virtual Machine from this Template…

We’re all admins with full rights over everything, so it wasn’t a permissioning issue (although I suspect it might be a permissioning bug).  The fix is to just re-add the Templates into the vCenter inventory (fuller details below if you don’t know how this is done). Continue reading →

In June 2011 VMware updated the secure key used for VMware Update Manager.  In order to prepare for this they made an update available well in advance, which would allow updates to continue.

However, if you need to reinstall an ESX from scratch, and your install method uses an older build, your rebuilt machine may be unable to update.  This is especially a problem for legacy ESXi environments, where you may be rebuilding using an old USB key image, which you’d need to go through the effort of recreating.  Chances are you’ll comes across this problem with the following error from the VI Client when you try to scan for updates or remediate…

VMware Update Manager had a failure

Continue reading →