Ok, I thought you downloaded a diagnostic from LSI (the actual manufacturer of the PERC controllers) :) "I have both array manager & OMSA installed on the server, are you suggesting to uninstall both & then re-install from scratch" I would, to get a correct and reliable view of the status of your storage.  OMSA has been around for a long time, and it used to be that Array Manager was required separately to manage storage, but years ago, Array Manager was discontinued and a storage portion was added to OMSA.  Just like matching drivers with firmware is important, matching drivers/firmware with an aligned version of OMSA is also important.  Depending on your version of OMSA, you may be able to simply uninstall Array Manager, then re-run OSMA setup to add the storage component. "Second option of replacing both the disks & the restoring server from backup sounds good but after 2 disks replacement & different results (each time 1 or more disks showing predictive failure) I am suspecting that its more to do with array but I am not sure" Agreed.  If you have already replaced disks and rebuilt them, performed a "rescan" on the controller (right-click PERC, Rescan), and it is still showing as degraded/pred-fail, then I would agree it is your array. "The Dell online diagnostics has very basic functionality, in main console it tells that the hard drive are healthy but nothing about array" There is no diagnostic for the actual array.  The diagnostics tests only the disks, but it is important to know if the disks are healthy or not.  If they fail diagnostics, then simply replacing the disks "may" be enough, although depending on the nature of the failure, even that may cause a rebuild to fail or drive to show pred fail.  If the disks do not fail diagnostics, that means  your drives are still good and your array is toast - a restore from backup to a freshly configured/initialized array (often times a file-level backup is required to get a good backup because of the damage) is usually the only way to "fix" it.
Hi all, by looking at the screen below, can you please advise if the backplane has failed or is it that suddenly all disks have failed? [IMAGE]
Is it total backplane failure or all disks have failed