PVS – Keeping you data persistent

Martin Zugec wrote a great blog on the Citrix blogs about keeping your data persistent with PVS (Provisioning Services). Here’s the beginning of his blog and at the end is a link to the entire post.

When to use persistent store

In theory, this is perfect solution – one to many, you’ve to manage only single image, all issues can be easily solved just by rebooting the machine. But what if you run into some showstoppers – for example one of your mission critical applications requires persistent data and doesn’t work in read-only mode?

When do you want to make your data persistent?

  • Applications that requires persistent storage – typically applications that will automatically generate machine-specific ID somewhere in configuration files – SCCM, antivirus…
  • Historical data that you want to keep for auditing andor troubleshooting – typically various log files
  • Improving overall performance – sometimes, keeping data persistent can improve your performance –for example redirection of page file and any frequently updates files (especially if they don’t use delta updates)
  • Special requirements – one of examples can be the license grace period or application streaming cache. Or applications with first run penalty
  • Security – there is a potential gap in security when you reset your computer to default state before it will download all updatescheck all requirements – similar to boot time protection of Windows Firewall, you may want to keep such data persistent

How to enable it

When you select “Cache on Target Device Hard Drive” option, new drive is automatically mapped for each provisioned machine. On this drive, you can find two important parts – write cache file itself and the rest of the drive. On reboot, only write cache file (.vdiskcache) is reset to default state, while the rest of the drive is persistent.

Read more here.