text: **12.4.4 Enabling encryption using both providers**
  
  IBM Spectrum Virtualize allows parallel use of both USB flash drive and one type of key 
  server (SKLM or SafeNet KeySecure) as encryption key providers. It is possible to configure 
  both providers in a single run of encryption enable wizard. To perform this configuration, the 
  system must meet requirements of both key server (SKLM of SafeNet KeySecure) and USB 
  flash drive encryption key providers. 
  
  **Note:**Make sure that the key management server functionality is fully independent from an 
  encrypted storage that has encryption managed by this key server environment. Failure to 
  observe this requirement might create an encryption deadlock. An encryption deadlock is a 
  situation in which none of key servers in the environment can become operational because 
  some critical part of the data in each server is stored on an encrypted storage system that 
  depends on one of the key servers to unlock access to the data. 
  
  IBM Spectrum Virtualize code V8.1 and later supports up to four key server objects that are 
  defined in parallel. 
  
  Before you start to enable encryption by using both USB flash drives and a key servers, 
  confirm the requirements that are described in section 12.4.2, “Enabling encryption using 
  USB flash drives” on page 622, and 12.4.3, “Enabling encryption using key servers” on 
  page 627. 