Virtual Servers and PACS

Posted Posted by Martin P in Infrastructure     Comments 2 comments

I note from HealthTech Wire that Fuji are

the first PACS vendor to officially validate its virtualization solution at VMware corporate headquarters in Palo Alto, Calif.

… Which may be true, but I’m glad to say that the number of PACS vendors which are qualified on virtual infrastructure continues to build. For the last 3 or 4 years in particular, server virtualisation is the only way to deliver servers in any medium- to large- sized organisation.

the benefits of virtualisation are well proven at this point:

  • Hardware consolidation means:
    • Reduced power consumption.  The typical non-virtual server room eats power (and the money it costs) at an obscene rate.
    • Increased reliability.  Each and every server can take advantage of the highly redundant hardware configuration traditionally reserved for only a handful of the most important servers.
  • Hardware abstraction, or the control of the environment which each instance of operating system sees as its hardware base.  This gives benefits:
    • Performance management.  Need extra processing power?  Just move the virtual server over to a different corner of the environment which has lower overall utilisation.  Simple as that.
    • Business continuity.  Especially when combined with good storage-level replication, the catastrophic loss of one of a pair of datacentres just means the servers need to be re-expressed in the other.

It is understandable perhaps that PACS vendors have been a little slow to qualify products in a virtual environment – there are two types of application in particular that perform less than optimally under virtualisation:

  • Applications with dependence on parallel processing.
  • Those with high IO demands – in terms of either volume or latency.

The latter of these clearly could be said to include PACS, but the evidence is now clear that PACS (at least good ones) does not have IO requirements that a virtual environment cannot deliver.

Which of the various flavours to invest in?  There are three main threads:

  1. VMWare is free to download and use (even if they have some archaic licensing hooks) and is widely recognised as being the industry leader – although this is primarily down to the technologies to do the ‘enterprise’ stuff like move VMs across hardware without downtime which itself comes at a price).
  2. Microsoft’s Hyper-V is also free with Server 2008. I can’t speak too much to this but I suspect like VMWare, to do any heavy lifting with require additional product which costs.
  3. The Xen family of vendors, including Oracle and Citrix leverage the Open Source (i.e. truly free) Xen Project.

Which is best for you is dependent on a number of factors – including your own appetite for risk. The biggest consideration though is the same as with selecting a PACS – be sure to chose a vendor (or in most cases, a reseller) that you can work with.

EDIT: Of course the 3 flavours mentioned above are the main ‘heavyweight’ options with big enterprise features.  There are many others more designed more for smaller shops or desktop environments.  Parallels is popular on the Mac, VirtualBox is popular on all platforms and KVM popular in a Linux environment.  For even more options (and there are many) check out the comparison page.

2 Comments to “Virtual Servers and PACS”

  • I work at a Hospital where we are going virtual with our FUJI PACS. i would like some information on what to know, ask, expect, results. Any information would be a great help, thank you.

    • Edward.. Virstualising *in general* should be a painless process.. What you are going to get out of it – and the things to watch out for will depend on your own cirumstances:

      1. Is this an existing virtual environment or entirely standlone? Will PACS be sharing infrastructure? Are you migrating an existing server or starting afresh?
      2. Which VM? VMWare, Xen? KVM?
      3. Objectives? What is the rational behind the virtualisation?


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