LaCie 4big Quadra RAID5 fail.


macrumors regular
Original poster
Aug 17, 2013
York, UK.
One of the drives failed on my LaCie 4big Quadra (4x HDD RAID5 array),
I installed a new drive to replace the failed drive everything looked fine then it failed to rebuild, red and blue lights start flashing in an order that's not in the manual! Now it turns on and will not mount... Can I take the 3x "Working" HDD's out install them in my Mac Pro 2010 and use some 3rd party software on my to access a LaCie RAID5 volume?

The drives show up in the Mac Pro as follows:

1. Master Boot Record
2. Uninitialized
3. Uninitialized
Last edited:


macrumors 65816
Nov 2, 2018
No. This is a common issue with RAID5, particularly when it’s populated with drives from the same batch.

One drive fails. Ok, pop in a replacement and let the array rebuild <boom> second drive fails under the sustained load of repopulating the new drive.

Array destroyed, data lost.


macrumors 6502
Aug 20, 2013
If it was me and the data was important I would image the 3 drives then use r-studio on Linux to rebuild the array. You have better chances of restoring data if the 3 remaining drives haven't failed and by using Linux.

Another option is to read more about what raiding software your lacie is using and mirror the same setup on a Linux vm. I have had success rebuilding failed readynas arrays. Took time but eventually succeeded.

  • Like
Reactions: LAHegarty