Currently viewing the tag: "ESX"

n+1 is hogwash!

By On 15 February 2010 · 3 Comments

Too frequently I hear the expression n+1 as a model for ESX clusters to provide High Availability.  If you EVER expect to patch ESX servers without VM downtime then you need at least(†) n+2.  When running your clusters to only n+1, you can never safely put one of your hosts in Maintenance Mode; not if High Availability is important [...]

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Don’t make /tmp too small

By On 13 November 2009 · 7 Comments

The default GUI install of ESX4 makes the /tmp partition 1GB and even then it is only categorized as optional.  I’ve been asked several times why you’d want to make /tmp any bigger.  If it fills up you just clear it out, right?

Well here’s a good reason.  It seems that VUM (vCenter Update Manager) [...]

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Firewall diagram – updated to version 3

By On 22 September 2009 · 4 Comments

Dudley passed me the latest version of the Firewall diagram.  Go and grab it:

Here’s what’s new since the last download:

What’s new in v3:
Now synchronized with “VMware Network Ports Compendium v3″

What’s new in v213:
Change port range in VUM to 9000-9100 (and [...]

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Permissions to cancel vCenter tasks

By On 24 June 2009 · 2 Comments

Here’s a strange one I’ve come across in vCenter 2.5.  You have a user, who is a member of an AD group, which has been assigned the Administrator role in vCenter over a Datacenter (or a folder, cluster, host, …) – but not at the root level.  Got that?  That user can do everything that [...]

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MSCS confusion

By On 18 June 2009 · 16 Comments

Configuring MSCS (MicroSoft Clustering Service) in the VMware world is a complicated process.  I’ve setup many MSCS solutions on VMware, and I still cringe when a customer demands it as a solution. It works, but every time I do it there are always so many little challenges.

I’ll try to describe what creates the most [...]

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ESX 3.5 patch 10 – what’s that?

By On 17 June 2009 · Leave a Comment

According to the vSphere 4.0 release notes (http://www.vmware.com/support/vsphere4/doc/vsp_esx40_vc40_rel_notes.html )

vCenter Server 4.0 becomes unresponsive in large environments if managing ESX Server 3.5 hosts prior to ESX 3.5 patch 10
vCenter Server 4.0 can become unresponsive in large environments after 30 days if it manages any ESX Server 3.5 hosts prior to ESX [...]

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Recreate header/descriptor vmdk files & recover failed Storage VMotion (DMotion)

By On 13 November 2008 · Leave a Comment

I had a another problem with Storage VMotion yesterday and found out a couple of interesting things.

Firstly, there is a now a Knowledge Base article explaining how to recreate vmdk header files if they are missing.  This was news to me, so here’s the link:

http://kb.vmware.com/kb/1004232

Secondly, was discovering a sightly different [...]

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Command prompt colours

By On 16 April 2008 · 1 Comment


Here’s an old trick which works great on ESX servers (thanks to this article on Linux Journal for reminding me).  It turns your prompt different colours to highlight when you are logged in as root.

To make the prompt red when you’re running as root add this to /root/.bashrc:

[...]

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Corrupted vmdk and vmsd files

By On 25 January 2008 · 3 Comments

I wanted to blog here about a silly mistake I made yesterday.

I need to expand a VM’s disk and was using the ol’ vmkfstools -X. However, I obviously do this all too flippantly and forgot to check if there was any snapshots. oops. That sunken feeling.

I corrupted the vmdk and the snapshot vmsd [...]

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