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White Paper: HR Firm Gets Shelter from the Storm with Centrinet’s IT Hosting

Resource Alliance, a leading national human resources solutions company, contacted Centrinet after a storm hit in late 2014, causing severe damage and power outages. The outages shut down their main server, prompting them to contract Centrinet for a long overdue environment overhaul. They had been experiencing performance issues with outdated end user devices and failing servers, and were in immediate need of a tailor-made solution.

Learn how Centrinet built a tailored solution to modernize Resource Alliance’s IT – and provide secure and reliable access to their critical business data – all while ensuring oversight and 24/7 IT support for the entire environment.

To read the full white paper, and learn the step-by-step details of the environment build, click here.

 

PVS vs. MCS in a VDI deployment

There’s a lot of debate in the engineering community on whether to use Provisioning Services (PVS) or Machine Creation Services (MCS) when deploying a VDI solution. There are clear differences between the two technologies, and depending on the type of deployment, important factors to consider when choosing which one to use.

MCS

MCS uses linked clone technology. This means that a snapshot is taken of the master template, which is then used as the parent disk for the clones (VDIs). This is a relatively simple method to deploy, and it doesn’t require any additional infrastructure.

Challenges of MCS 

The main challenges of MCS are storage and scale-out related. With MCS, the clones and the parent disk must be on the same datastore in order to maintain link integrity. If the linked clones are distributed across multiple datastores, a copy of the master must be as well – substantially increasing the storage requirements for a deployment. For this reason, scaling out an MCS deployment can become difficult.

  • MCS uses about 21% more IOPS than PVS. Depending on the network infrastructure, this may be an important factor to consider for maintaining consistent performance across the VDIs.
  • MCS does not regularly “clean up” old master clones when deploying an update from a new snapshot. Instead, the old files must be manually removed in order to free up disk space.
PVS

PVS uses software streaming technology to deliver VDIs, requiring additional infrastructure to support the solution. PVS imaging wizard captures an image from the master machine, and then stores it in a VHD format (vDisk) on the Provisioning Server. The vDisk can then be shared (streamed) by multiple VDIs.

Technical Note: PVS utilizes a PXE boot method (BDM can also be used in the absence of DHCP) and a TFTP to stream the vDisk. Additional network configurations are required to allow PXE to work in the environment.

PVS is an elegant solution, and scales well in large enterprise-class deployments. Multiple PVS servers can be built out to balance the vDisk streaming load, providing redundancy as needed. And, with the introduction of caching to device RAM, the IOPS used by a PVS deployment can be greatly reduced (<1 IOP in some cases).

Summary

MCS is suited for small deployments (or lab scenarios) and is simple to deploy. But overall, PVS is the more robust and scalable solution for enterprise environments.

PVS requires more intensive planning, additional infrastructure, and more configuration to implement. However, once built it’s easy to maintain and requires very little maintenance. In most scenarios, it would be preferable to deploy PVS as opposed to MCS for the reasons outlined above.

 

Here at Centrinet we keep up-to-date on the latest technologies – and like to make sure you do too. Contact us today to learn more about our suite of datacenter virtualization and management services.

 

Provisioning Services (PVS) and Daylight-Saving Time

With daylight-saving time beginning at week’s end (March 8 at 2am), we wanted to provide an overview of the issues that can occur with PVS delivered desktops and XenApp servers.

Some of the issues that occur as a result of the time change are:

  • Time not showing correctly in the Desktop or XenApp server,
  • Desktop failure to register with DDCs,
  • User inability to log on due to domain trust relationship issues caused by the VM/Domain time difference.

The Fix:

  1. Open up your PVS delivered image(s) in read/write mode after the time change has occurred on Sunday.
  2. Run w32tm /resync /nowait” at the command prompt.
  3. Set the image(s) back to read only, following your normal image preparation procedures.

Remember, you must reboot all PVS delivered desktops and servers after you make the above changes to ensure they receive the updated version.

Being proactive will help ensure a smooth Monday morning for all of your users!

More information on this issue can be viewed here: http://support.citrix.com/article/CTX200058

Notable Citrix Updates

A couple of weeks back I was able to attend the 2015 Citrix Summit in Las Vegas. The event was a great resource – with sales education, technical deep dives, and an array of new programs. One great bonus was the fact that it was held in January, so I didn’t have to suffer the 110°+ heat of a Las Vegas summer.

There are three releases I want to make special note of – these are releases we have had success with, along with great client feedback. So without further ado, here are my top three notable Citrix updates from the Summit:

  1. XenApp and XenDesktop 7.6 updates: There have been changes in graphic engines, with H.264 becoming the new industry standard. With the release of the 7.6 updates, Citrix is moving in that direction as well.
  •   For detailed product information please click here.
  1. PVS Cache in RAM, with overflow to Hard Disk (HD): This is a great new feature on PVS, because you can eliminate the need for expansive storage. We have clients currently using this feature, and they can’t tell the difference between 3PAR SATA Hard Drives and Whiptail SSD.
  •   For detailed product information please click here.
  1. GPU into XA/XD: We have successfully deployed AutoCAD for some of our clients via XenApp, and so far the feedback has been great. One client said, “The performance is as good as if it were locally installed”.
  •   For detailed product information please click here.