After a power failure the Promise Pegasus R4 reports all disks drives as dead. But this is almost impossible! Is there any way to "reset" the Promise Pegasus without losing all data?

The unit is connected to a Mac Mini and I have the Promise software installed.


The official and easier way to recover is:

On Mac, open the Terminal and run:


This will open the promise utility. Now type the following commands:

phydrv -a online -p 1
phydrv -a online -p 2
phydrv -a online -p 3
phydrv -a online -p 4

If you have the R6 version add this commands before exit the utility:

phydrv -a online -p 5
phydrv -a online -p 6

After you force the drive online, reboot the unit and you will have access to the data.

  • It should be noted that your excellent answer also is applicable should when plugging in the thunderbolt connection, etc - any one drive randomly reports as 'DEAD'. For whatever reason the Promise Utility GUI can't simply 'Force Online' the way this command can. Great answer. Thanks. – Gabriel Aug 23 '13 at 12:10
  • Thank you ! I had a sudden massive fright when I simply removed all the disks from the Pegasus R4, and upon reinserting they all showed as dead... And the graphic utility is absolutely useless in recovering from this situation – jyavenard Sep 28 '14 at 9:57

protected by Community Aug 11 '13 at 6:49

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