I'm having Pegasus R4 along with 2TB drives. I'm starting to notice that it won't mount on the iMac. Power button is on but the drive is showing blue color.
And after turning it off, and removing the drives, and plugging the cables again, i am able to see that one of the three hard drives is only showing a single blue light instead of two blue lights like the other two drives.
We need to analyse the logs to see if any error in the drives and possible options to mount the drive .Please open support case at https://support.promise.com and attach the service report for further investigation
Steps to save the subsystem report :
1) Open Promise Utility.
2) Click subsystem information icon on the top of the window.
3) Click the lock symbol on the left bottom corner of the screen to unlock the utility.
4) Click on save service report button to save the subsystem report and attach it to this case