The State of Monitoring

System and Service Monitoring is something that I believe doesn’t get enough attention. Having visibility into the services you’re responsible for is an absolute must for any operations team. Finding out via a phone call or escalation that a critical service can certainly be a resume generating event. While some organizations have a dedicated team for such systems, most Sysadmins and Operations teams are left to figure this critical component out on their own.

The average monitoring software performs a check every few minutes, determines if the current state falls within a certain threshold, and then alerts someone to the change in status. I can hear you now – “Duh! What else would it do?” The problem with this archaic interpretation of monitoring is that thresholds are arbitrarily set and may not indicate an actual issue. A storage volume that was at 84% utilization yesterday, and is now 85% utilized today, is likely not a problem. Just because a service is running, doesn’t mean it’s functioning as expected. Why would I not want a database server to not use 90% of it’s memory? These are just some of the flaws in static threshold monitoring systems.


Configuring Citrix Desktop Director 2.1 for use with Citrix XenApp 6.5

Citrix Desktop Director is a fantastic new product from Citrix that’s bundled with Citrix XenApp 6.5+ and XenDekstop 5.5+. It’s a web-based service desk console that allows for easy and fast access to user information (search by name!) that includes which server/virtual desktop they’re connected to, their endpoint name and location, information from their AD account (phone number, address, etc.), connection information (Citrix HDX status, client version). The service desk can log users off, disconnect sessions, send users’ messages and shadow sessions all from their browser!


Creating a XenApp 6.0 Lab Using Amazon EC2

Not everyone has access to equipment at home or work to learn, experiment or test software. It often requires a pretty good chunk of money up front to get started – that won’t fly for everyone. For those who want access to fast, reliable and affordable computing power, the cloud is the perfect place to look. In this article we’ll cover building a 2 server lab to run Citrix XenApp 6.0 and a Domain Controller on Windows Server 2008 R2 on Amazon’s Elastic Computing Cloud (EC2).


VMware ESX 3.5 Update Manager Failure

If you are suddenly (June 2011) unable to Scan for Updates or Remediate VMware ESX 3.5 Hosts, you may be without ESX350-201012410-BG (VMware KB 1030001). When running ESXUpdate via SSH on the host, you’ll receive an Integrity Error that includes:

Signature 0BFA1C860F0B0A6CF5CD5D2AEE7835B14789B619: keyExpired: 4789B619

To resolve this, you’ll need to bypass the Signature Requirement for patching so the new Secure Key Patch can be applied. To do this, connect via SSH to the host, and run the following command.

esxupdate -d http://patchdepoturlhere --nosig update

This will install all updates and reboot the host, so be sure it’s in maintenance mode prior to running the command. After the host has been patched in this method, you’ll be able to use the VUM GUI again.


XenDesktop Setup Wizard: SR_BACKEND_FAILURE_44

When using the Citrix XenDesktop Setup Wizard on your Provisioning Services server, you may encounter this error when creating new virtual desktops from a template.

Unable to create the desktop DESKTOPNAME.
Unable to clone the virtual machine for this desktop.
Exception thrown : SR_BACKEND_FAILURE_44
Unable to provision a vDisk for the desktop.

This error often appears when there is no longer sufficient space on your Storage Repository to clone the VM Template. To resolve this, either remove the storage requirement from your template (if it’s not needed) or add additional space to the desired storage repository.