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Sending an email Programmatically using Java

This article will decribe how you can send emails programatically using hte Java programming language. The example below includes a function you can use for easily sending emails from your Java application.PrerequisitesIf you have not already, be sure you download and install the latest Java Development Kit (JDK). You can find the download here.Unforutnatley the javax.mail libraries are not included in the Java JDK, so you will have to download them separately.The java mail library can be downloaded Read more […]

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Virtual machine(s) invalid in vCenter

Sometimes virtual machines within your VMWare environment may show up as invalid. The machine is in-fact still running at this point; but you are unable to manage the virtual machine. This can happen for a few reasons, but in my experience the most common is when the esx host is unable to access the storage.

I have seen this caused by high latency when accessing an NFS datastore, when you leave an offline datastore mounted for an extended period, and I have also seen this happen when a SAN controller failover event occurs.

This condition happens when the esx host cannot access the vmx file (vmware configuration file) in the datastore, so VMWare just sort of forgets the configuration of the machine. The process which runs the virtual machine is still running on the host, so your VM does not crash. But, you still need to recover since HA, DRS, etc… no longer work when the VM is in this state.

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Scripting Basics

Scripting is a very useful skill which will save any Sysadmin a lot of time. Who wants to go to every device in their environment and perform the same task over and over again? In this posting I will cover a few basics for those getting started in scripting.