Bug report originally reported to gparted: https://bugzilla.gnome.org/show_bug.cgi?id=784976 But from second comment it appears that real problem is in parted, because gparted only used parted. See: # truncate -s 10G /tmp/gpt # parted /tmp/gpt GNU Parted 3.2 Using /tmp/gpt Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) mklabel gpt Warning: The existing disk label on /tmp/gpt will be destroyed and all data on this disk will be lost. Do you want to continue? Yes/No? yes (parted) quit # dd if=/tmp/gpt bs=1 count=16 skip=446 2>/dev/null | xxd 00000000: 0000 0100 eefe ffff 0100 0000 ffff 3f01 ..............?. Original bug report: According to _UEFI Specification 2.6_, section _5 GUID Partition Table (GPT) Disk Layout_, subsection _5.2.3 Protective MBR_, Table 17. _Protective MBR Partition Record protecting the entire disk_, **StartingCHS** is 0x000200 (**0/0/2**) and **EndingCHS** is 0xFFFFFF (**1023/255/63**) if it is not possible to represent last logical block as C-H-S. But When creating new GPT partition table via gparted StartingCHS is 0/0/1 and EndingCHS is 1023/254/63 which is incorrect. Please make gparted compliant to UEFI/GPT specification. Test to reprocude: $ truncate -s 10G /tmp/gpt $ sudo ./src/gpartedbin /tmp/gpt (now create new GPT partition table in menu and exit) $ dd if=/tmp/gpt bs=1 count=16 skip=446 2>/dev/null | xxd 0000000: 0000 0100 eefe ffff 0100 0000 ffff 3f01 ..............?. StartingCHS is 0x000100 (1st byte - 4th byte) which means 0/0/1 EndingCHS is 0xfeffff (5th byte - 8th byte) which means 1023/254/63 When creating new gpt partition table with gdisk, Protective MBR is filled correctly: $ truncate -s 10G /tmp/gpt2 $ printf "o\ny\nw\ny" | gdisk /tmp/gpt2 $ dd if=/tmp/gpt2 bs=1 count=16 skip=446 2>/dev/null | xxd 0000000: 0000 0200 eeff ffff 0100 0000 ffff 3f01 ..............?. StartingCHS is 0x000200 (1st byte - 4th byte) which means 0/0/2 EndingCHS is 0xffffff (5th byte - 8th byte) which means 1023/255/63 Btw, same problem had fdisk from util-linux... https://github.com/karelzak/util-linux/issues/485 -- Pali Rohár pali.rohar@gmail.com