Jerry Case
posted this
15 April 2016
If you have RAID 5 configured for your logical drive, then you can be one disk down and still have the data be readable.
What you probably saw was the replacement disk, when coming from the manufacturer, will often have a partition already on the disk. If this is the case, the disk will show up in the list of available disks as 'pass thru'
Pass through just presents the disk to the computer to be used as a regular disk drive and not being handled by the Pegasus
You have to change any Pass Thru drives to unconfigured before the disk will be used to rebuild an array.
Even with one disk down, three disks online and the array online the disk array should list as degraded and the logical drive as critical. Critical because is you lose one more disk, then you do lose your data by any regular means of reading it. However a data recovery service may be able to get the data back for a price.
As with any hard disk drive, disk array or any storage for that matter, it is a good idea to have back-up of the data.
RAID levels 1 and higher have some level of fault tolerance but that's just tolerance, not fail proof. It won't protect from drive fails greater than the design of the RAID can lose and it is not protected for any kind of disaster.
You said the utility won't start now. It won't start if it's not able to detect the Pegasus. So with it attached, go to the Mac's terminal screen and in the window, type 'promiseutil' like you had before to get to the first phydrv command.
if you start the promise utility from the terminal window, type 'phydrv' to list all the disks. Drives 1, 2 and 3 should be unchanged as your first message. Drive 4 should be detected but then you can see if it's on pass thru or not.
Also, the firmware update is not a disk image to mount on the Mac. It's an image file passed to the Pegasus through the utility to install.
However our latest update is now available on automatic updates, so just launch your utility and check for updates.
Best Regards
Jerry - Promise Technology