The default SAN policy in WinPE 4.0 is to mount available disks automatically. This might reduce the performance of WinPE if there are many available disks in the SAN environment. By using the setsanpolicy.cmd file in the WinPE tools path, the default SAN policies can be configured, and a new WinPE image created.

Source: http://technet.microsoft.com/en-us/library/cc749466%28v=WS.10%29.aspx.

Solution 1: Shut down the Active node, boot to the Recovery Disk (SRD) on the passive node, and perform system restore

Solution 2: If it’s not possible to shut down the Active node, the BOOT.WIM file on the SRD can be modified. Please follow the instruction in the following Microsoft article: https://technet.microsoft.com/en-us/library/cc749466%28v=WS.10%29.aspx

Use the following steps for modifying the SRD:

1. Extract the .iso file using a third-party tool
2. Mount boot.wim using the following command: Dism /Mount-Image /ImageFile:\SOURCES\boot.wim /index:1 /MountDir:
3. Make the necessary changes (see above)
4. Commit the changes to boot.wim using: Dism /Unmount-Image /MountDir:"" /commit

For more details, please refer to: https://technet.microsoft.com/en-in/library/hh824814.aspx.

Once complete, boot the passive node using the modified SRD. All volumes will show up as offline. Make online only boot and system volumes and perform system restore. (Note: Because this solution requires the boot.wim on the SRD to be modified, these steps require a writable location such as a USB SRD or the LightOut Recovery Environment. Modifying boot.wim is possible only on writable media.)