This is more of a note for future reference rather than a blog post.
I recently had to replace a RAID-10 member disk as the original disk had developed bad sectors and was causing mostly read related problems in the array. (That’s a whole other story it it’s won right and I don’t have time to get into that now). However, when I tried adding the replacement disk to the server, I found that the disk had a GPT table and not an msdos partition table, unlike the other 3 members in the RAID array. I was therefore unable to add the disk “as-is” to the RAID array as all disks are required to have the same partition table type. I therefore needed to remove the GUID Partition Table and replace it with an msdos partition table.