Adding Virtual Disks and “Operating System not found”

I ran into a frustrating issue the other day when attempting to add multiple new virtual disks to an existing VM. Upon doing so, I received the dreaded “Operating System not found” message when the VM was started. While the underlying issue was easy to discover, the way to fix the problem became tedious due to issues with the vSphere web client. This post contains some tips and tricks to make the process easier.

os-not-found

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Changing VMware ESXi host logging level and why not to do it

A while back, I came across an entry from Michael White’s newsletter about changing VMware ESXi host logging levels:

Changing VMware ESXi host logging level
Someone was talking about doing this, and using this as a guide, but I would like to say you may not want to do this.  There may be a reason for the log levels, and if you change them it may be harder to support you if you call VMware for help.  And your syslog of choice should be able to handle the volume and I know – in fact better than most – that ESXi logs are noisy, but you can deal with that with good searching.

I completely agree with Michael and this post will explain why.

vsphere

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Configuring Remote Syslog on vSphere Using vCenter Log Insight

Now that you have vCenter Log Insight deployed and configured, you need to configure sources to send their log messages to Log Insight. If you enabled vCenter Server integration then you should start to receive log messages, but this is only the beginning of configuring remote syslog sources.

IMPORTANT: Configuring vCenter Server integration does not configure vCenter Server or ESX/ESXi hosts connected to vCenter Server to send remote syslog to Log Insight. For more information continue reading!

Let’s start by going over what Log Insight supports today and what mechanisms it has to configure vSphere devices for you.

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Rescan All Hangs ESXi

I ran into a interesting problem the other day. I was brought into an environment that had a pair of ESXi 5.1 hosts connected to an iSCSI datastore. One host could see and access the datastore without issue while the other host showed no datastore attached. Per the administrator both hosts had been mounted to the datastore and the claim was that the environment had not be touched/changed in any way.

What was going on and how can you fix it?

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