My ThinkStation runs CentOS 7 which I installed on a BIOS RAID 0 setup with two identical 256 Gb SSDs after removing Windows. It runs fine but I just discovered in gparted something that does not seem right: - Launching gparted it complains "invalid argument during seek for red on /dev/md126" and when I click on Ignore I get another error "The backup GPT table is corrupt, but the primary appears OK, so that will be used." I then click on OK whereupon I again see the second error message. I then see "Not all of the space available to /dev/sdb appears to be used, you can fix the GPT to use all of the space (an extra 6832 blocks) or continue with the current setting? " I click on Fix but nothing seems to happen. I am not sure what /dev/md126 is but it is the exact same size as sda and sdb which I believe are the two RAID disks. I also have two other hard disks which seem to be fine, one using XFS, the other ZFS. Does this look familiar to anyone? Given the error messages it seems this is something I ought to fix sooner rather than later. Any idea what I should do? Thanks.