Upgraded MyBook World II to 2x4 TB hard drives – but only 2x2 TB is detected!?


I use my MBWE II to back up my Macs via Time Machine. The MBWE is configured to use RAID (mirror), and I used to have two 2TB hard drives in it. I needed to get more space for backup, so I bought two 4TB hard drives. I put one in, and waited until both disks had the status “Good”. I then removed the second 2TB hard drive and put in the second 4TB hard drive.

All is well, and both disks’ status is “good”. However, while both disks seem to be OK, the MBWE seems to think that there are still only two 2TB hard drives in it! (See picture below)

Still, the Disk Manager reports that two 4TB hard drives are installed (see image below).

So, how can I make the RAID system “see” all 4TB worth of hard drive for my backup?



No, your MBWE is perfecly aware that you changed the drives and that they’re larger.

You did NOT increase the VOLUME size.

You’ll have to delete the volume, and create a new volume to make use of the full space of the RAID array.

And, yes, that will delete all of your data.

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Arrgh! I thought I could just swap them, and let my backups grow indefinitely… 

Thanks though, for your quick reply. I still have the old 2TB disks lying around. Do you think a possible work-around is to create a new volume as you suggest and copy the data from the old disk(s)? Do you perhaps also know how to do this, or can you point me in the right direction?



I’m not sure – I’ve actually never used an MBWE – I just see similar issues on all kinds of NAS platforms so I recognized it when I saw it – it’s a common thing.

OK. Thanks anyway.

So, here we go. Formatting time! :smiley: