Converting a system with a large amount of locally attached storage can be a challenging task given the time required to perform the conversion. Here area a few tricks I’ve found that can help ease the pain on these types of conversion tasks.
- Private network: Making a private network between the physical host and the virtual host can provide two benefits. The main benefit is that conversion traffic will be isolated from the rest of the network traffic; the other advantage is that there is no risk of a user or process connecting to any resources and making changes during the conversion. The downside is that there may be special host-side configuration for a temporary network presence to allow the special network.
- Direct LUN mappings: For virtualization platforms that allow guest VMs to access a LUN directly, it can be much easier than performing a lengthy conversion of large data volumes that are already on a storage area network (SAN) and mapped to a physical system. Here is a blog post with a little more detail on that topic.
- Housekeeping: If there is junk on the physical system, does it need to be converted to the virtual environment, which may have more expensive storage? Clean up the candidate’s file system, and perform obvious tasks like emptying the Windows Recycle Bin. This allows for a more accurate re-sizing of the drives during the conversion.
- Agent backup and restore: For standard file volumes, such as a file server, it may make more sense to only convert the system drive and perform an agent-based restore to the virtual machine for the additional volumes. This does not necessarily save time from the entire conversion, but saves time within a tool like VMware Converter.
- Get a good time estimate: If you have to go at the large storage system as-is, make sure you have a baseline of about how many GB can be converted per hour. A good way to test this is to convert a good candidate system of about 100 GB and use that as a multiplier for your environment. There are a lot of factors, such as network speed and traffic, virtualization platform, storage systems (on both ends), and the conversion mechanism used. This allows for a good estimate on any downtime that needs to be coordinated if this applies to the selected workload.
These tricks can make converting a large amount of storage a little less daunting. What tricks have you employed to tackle physical systems with large amounts of storage in the course of being converted to a virtual machine? Leave a comment below and let us know.