If SIOS AMIs are not being deployed on an AWS server, these disk initialization steps must be considered. This was introduced with Windows 2016 and continues in later releases.

  • AWS ephemeral storage (Instance Store) must be initialized every time a node starts up from a “cold” shutdown (i.e. having been shut down in the AWS Console or from a CLI “shutdown /s” from Windows – not a reboot).
  • Windows 2012 R2 performs this step automatically (Ec2Config service). AWS includes scripts (EC2Launch) to perform this initialization but the script has to be manually scheduled by the user so that it runs at boot time.
  • The SIOS AMIs on AWS have this task set up automatically. If you launch your own Windows image in AWS and fail to set the script up to run at boot, and you are using ephemeral storage for bitmaps (recommended), the bitmap file/volume will be missing and DataKeeper mirrors will not recreate.


Launch Disk Management and make sure the ephemeral storage is on-line, healthy, and is assigned the volume letter you selected for the ephemeral storage.
Ensure that the drive/drive letter assigned to the ephemeral storage is listed in the registry located at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ExtMirr\Parameters . . . BitmapBaseDir


Schedule the EC2Launch script to run at boot time on each system in the cluster to ensure that the ephemeral storage is always available.


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