SCVMM R2: How to improve BITS performance during Migration Jobs


SCVMM migration transfers are slow


In SCVMM R2 BITS transfers are set to be encrypted by default


If you have implemented another form of encryption, such as IPsec, or have otherwise secured your virtualized environment, you might want to take advantage of the new option in VMM 2008 R2 to allow unencrypted file transfers for individual library servers and individual host groups. Allowing unencrypted file transfers can improve performance during virtual machine creation and migration. For files to be transferred unencrypted, unencrypted file transfers must be allowed on both the source and destination computer. This option is available by updating the properties of a library server.

Disable Bits encryption for both Hosts and the SCVMM Library:

Disabling SCVMM 2008 R2 Encrypted Transfers for Hosts
  1. Open the VMM Administrator Console
  2. Depending on your environment configuration, select the Host Groups (e.g. All Hosts) that has all of your Hyper-V hosts
  3. Right-click on the Host Folder (e.g. All Hosts)
  4. In the ‘Allow Unencrypted file transfers’, check the box

Disabling SCVMM 2008 R2 Encrypted Transfers for Libraries

  1. Open the VMM Administrator Console
  2. Click the Library tab (displays Library servers, assets)
  3. Right-click on the library server and select properties
  4. Check the ‘Allow unencrypted file transfers’
  5. Click OK

More Information


How to Modify the Properties of a Host Group

How to Allow Unencrypted File Transfers for a Library Server

Hardening VMM Library Servers

For the following issues please reference the blog post below:

1.     Deployment or migration of data utilizing LAN (not SAN Transfer) is very slow in general
2.     BITS is slow in one direction only: Fast from Host01 to Host02, but slow from Host02 to  Host01 for example
3.     Host reports in SCVMM Admin Console "Host not responding" or "Needs attention"
4.     Under 'Status' of the Host the following may show "Not Responding"
    - Connection status
    - Agent Status

How to Troubleshoot Slow BITS Performance, Hosts 'Not Responding' and 'Needs Attention' Communication Issues


Article ID: 2625478 - Last Review: Jan 7, 2017 - Revision: 1