HowTo Create A GPT Disk With EFI System And exFAT Partitions Using Parted
Overview
The purpose of this article is to create a disk that can be read / written to by all major operating systems (i.e., macOS, Windows and Linux). A removable USB storage device containing SSD SATA or NVMe media formatted with an exFAT partition can be used to accomplish this. At the time of this writing, January 02, 2020, a removable USB-C drive containing a CORSAIR FORCE Series MP500 120GB NVMe storage device will be demonstrated.
The USB drive is attached to an NST system as device: "/dev/sdc". The parted disk utility will be used to create a GUID Partition Table (GPT) disk label, the EFI System Partition and the exFAT partition. GPT partitioning allows one to use all available disk space for disk drives that exceed 2TB in size. The is one of the limitations for legacy MBR partitioning.
The following diagram is an example GUID Partition Table layout:
Zero Out Previous Disk Label - Optional
This optional step will zero out any previous disk label. We will use the dcfldd utility. The first 1GB of the disk will be zeroed out:
[root@shopper2 ~]# dcfldd if=/dev/zero of=/dev/sdc statusinterval=64 bs=1M count=1k; 1024 blocks (1024Mb) written. 1024+0 records in 1024+0 records out [root@shopper2 ~]#
We can now used parted to examine the disk and see that we are starting out with an "unrecognized" disk structure:
[root@shopper2 ~]# /sbin/parted -s /dev/sdc print; Error: /dev/sdc: unrecognised disk label Model: JM583 (scsi) Disk /dev/sdc: 120GB Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags: [root@shopper2 ~]#
Create GPT Disk Label
The GPT disk label will now be created:
[root@shopper2 ~]# parted /dev/sdc; GNU Parted 3.2 Using /dev/sdc Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) mklabel gpt (parted) quit Information: You may need to update /etc/fstab. [root@shopper2 ~]# /sbin/parted -s /dev/sdc print; Model: JM583 (scsi) Disk /dev/sdc: 120GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags [root@shopper2 ~]#
Create EFI System Partition
A new EFI System Partition will be created using the following commands (the recommended size is at least 260 MiB):
[root@shopper2 ~]# parted /dev/sdc; GNU Parted 3.2 Using /dev/sdc Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) mkpart primary fat32 1MiB 261MiB (parted) set 1 esp on (parted) print Model: JM583 (scsi) Disk /dev/sdc: 120GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 274MB 273MB fat32 primary boot, esp (parted) quit Information: You may need to update /etc/fstab. [root@shopper2 ~]#
Create exFAT Partition
A new exFAT partition will now be created using the remaining unused disk area:
[root@shopper2 ~]# parted /dev/sdc; GNU Parted 3.2 Using /dev/sdc Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print Model: JM583 (scsi) Disk /dev/sdc: 120GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 274MB 273MB primary boot, esp (parted) mkpart primary ntfs 261MiB 100% (parted) print Model: JM583 (scsi) Disk /dev/sdc: 120GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 274MB 273MB primary boot, esp 2 274MB 120GB 120GB ntfs primary (parted) quit Information: You may need to update /etc/fstab. [root@shopper2 ~]# /sbin/parted -s /dev/sdc print; Model: JM583 (scsi) Disk /dev/sdc: 120GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 274MB 273MB primary boot, esp 2 274MB 120GB 120GB primary msftdata [root@shopper2 ~]#
Format exFAT Partition
Use the "mkfs.exfat" command to format the exFAT file system:
[root@shopper2 ~]# mkfs.exfat -L NVMe /dev/sdc2 mkexfatfs 1.3.0 Creating... done. Flushing... done. File system created successfully. [root@shopper2 ~]#
The "lsblk" command shows the newly created exFAT file system with label:
[root@shopper2 ~]# /bin/lsblk -a -o name,label,size,fstype,model /dev/sdc; NAME LABEL SIZE FSTYPE MODEL sdc 111.8G USB3.1_NVME_DISK ├─sdc1 260M └─sdc2 NVMe 111.5G exfat [root@shopper2 ~]#
Summary
The newly formatted disk should now be read / written to by all major operating systems (i.e., macOS, Windows and Linux). If not use the method below: Alternate exFat Partition Creation For OS Interoperability.
Alternate exFat Partition Creation For OS Interoperability
This section will show the steps on how to create an entire exFAT partition on a USB 64GB flash drive so that all major OSs (i.e., i.e., macOS, Windows and Linux) can mount and use the data on the drive.
1) Discover the target USB drive to create the exFAT partition with fdisk. In this case it will be "/dev/sda"
[root@dell7480 ~]# fdisk -l; Disk /dev/nvme0n1: 476.94 GiB, 512110190592 bytes, 1000215216 sectors Disk model: FPI512MWR7 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: B276CCFE-BD35-4510-9E92-B6E44CEEFAE8 Device Start End Sectors Size Type /dev/nvme0n1p1 2048 1230847 1228800 600M EFI System /dev/nvme0n1p2 1230848 3327999 2097152 1G Linux filesystem /dev/nvme0n1p3 3328000 1000214527 996886528 475.4G Linux filesystem Disk /dev/zram0: 8 GiB, 8589934592 bytes, 2097152 sectors Units: sectors of 1 * 4096 = 4096 bytes Sector size (logical/physical): 4096 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk /dev/sda: 57.3 GiB, 61530439680 bytes, 120176640 sectors Disk model: SanDisk 3.2Gen1 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes [root@dell7480 ~]#
2) Make sure the USB flash drive is not mounted. Example: USB drive mounted at: "/run/media/nst/59DF-5291"
[root@dell7480 ~]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 7.8G 0 7.8G 0% /dev tmpfs 7.8G 0 7.8G 0% /dev/shm tmpfs 3.1G 2.0M 3.1G 1% /run /dev/nvme0n1p3 476G 8.1G 467G 2% / tmpfs 7.8G 2.1M 7.8G 1% /tmp /dev/nvme0n1p3 476G 8.1G 467G 2% /home /dev/nvme0n1p2 976M 248M 662M 28% /boot /dev/nvme0n1p1 599M 17M 583M 3% /boot/efi tmpfs 1.6G 96K 1.6G 1% /run/user/1000 tmpfs 1.6G 72K 1.6G 1% /run/user/0 /dev/sda1 58G 12M 58G 1% /run/media/nst/59DF-5291 [root@dell7480 ~]# [root@dell7480 ~]# umount -v /run/media/nst/59DF-5291 umount: /run/media/nst/59DF-5291 (/dev/sda1) unmounted [root@dell7480 ~]#
3) Use fdisk to remove any previously created partitions, create a GPT partition table and then make a new partition (i.e., "/dev/sda1") for exFAT using the entire USB drive.
[root@dell7480 ~]# fdisk /dev/sda;
Welcome to fdisk (util-linux 2.36.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x997a9a9d.
Command (m for help): d
No partition is defined yet!
Command (m for help): g
Created a new GPT disklabel (GUID: 7D769FCD-8E49-9944-B4BA-C418633F0C4E).
Command (m for help): n
Partition number (1-128, default 1):
First sector (2048-120176606, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-120176606, default 120176606):
Created a new partition 1 of type 'Linux filesystem' and of size 57.3 GiB.
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
[root@dell7480 ~]#
4) Show partition creation progress using parted.
[root@dell7480 ~]# /sbin/parted -s /dev/sda print; Model: USB SanDisk 3.2Gen1 (scsi) Disk /dev/sda: 61.5GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 61.5GB 61.5GB [root@dell7480 ~]#
5) Make sure the boot record is converted to GPT.
[root@dell7480 ~]# gdisk /dev/sda; GPT fdisk (gdisk) version 1.0.8 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Command (? for help): w Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING PARTITIONS!! Do you want to proceed? (Y/N): Y OK; writing new GUID partition table (GPT) to /dev/sda. The operation has completed successfully. [root@dell7480 ~]#
6) Set the partition type to: "msftdata" - Microsoft Basic Data
[root@dell7480 ~]# parted /dev/sda; GNU Parted 3.4 Using /dev/sda Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) set 1 msftdata on (parted) q Information: You may need to update /etc/fstab. [root@dell7480 ~]#
7) Show partition progress.
[root@dell7480 ~]# parted -s /dev/sda print; Model: USB SanDisk 3.2Gen1 (scsi) Disk /dev/sda: 61.5GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 61.5GB 61.5GB msftdata [root@dell7480 ~]#
8) Now format partition: "/dev/sda1" as an exFAT file system using: mkfs.exfat with label: "THUNDER2-1" with verbose mode on.
[root@dell7480 ~]# mkfs.exfat -v -L THUNDER2-1 /dev/sda1; exfatprogs version : 1.1.2 [exfat_get_blk_dev_info: 202] Block device name : /dev/sda1 [exfat_get_blk_dev_info: 203] Block device offset : 1048576 [exfat_get_blk_dev_info: 204] Block device size : 61529374208 [exfat_get_blk_dev_info: 205] Block sector size : 512 [exfat_get_blk_dev_info: 206] Number of the sectors : 120174559 [exfat_get_blk_dev_info: 208] Number of the clusters : 469431 [exfat_zero_out_disk: 516] zero out written size : 3538944, disk size : 61529374208 Creating exFAT filesystem(/dev/sda1, cluster size=131072) Writing volume boot record: [exfat_setup_boot_sector: 81] Volume Offset(sectors) : 2048 [exfat_setup_boot_sector: 83] Volume Length(sectors) : 120174559 [exfat_setup_boot_sector: 85] FAT Offset(sector offset) : 2048 [exfat_setup_boot_sector: 87] FAT Length(sectors) : 3840 [exfat_setup_boot_sector: 89] Cluster Heap Offset (sector offset) : 6144 [exfat_setup_boot_sector: 91] Cluster Count : 469407 [exfat_setup_boot_sector: 93] Root Cluster (cluster offset) : 4 [exfat_setup_boot_sector: 95] Volume Serial : 0xff393695 [exfat_setup_boot_sector: 96] Sector Size Bits : 9 [exfat_setup_boot_sector: 98] Sector per Cluster bits : 8 done Writing backup volume boot record: [exfat_setup_boot_sector: 81] Volume Offset(sectors) : 2048 [exfat_setup_boot_sector: 83] Volume Length(sectors) : 120174559 [exfat_setup_boot_sector: 85] FAT Offset(sector offset) : 2048 [exfat_setup_boot_sector: 87] FAT Length(sectors) : 3840 [exfat_setup_boot_sector: 89] Cluster Heap Offset (sector offset) : 6144 [exfat_setup_boot_sector: 91] Cluster Count : 469407 [exfat_setup_boot_sector: 93] Root Cluster (cluster offset) : 4 [exfat_setup_boot_sector: 95] Volume Serial : 0xff393695 [exfat_setup_boot_sector: 96] Sector Size Bits : 9 [exfat_setup_boot_sector: 98] Sector per Cluster bits : 8 done Fat table creation: [exfat_create_fat_table: 307] Total used cluster count : 5 done Allocation bitmap creation: done Upcase table creation: done Writing root directory entry: done Synchronizing... exFAT format complete! [root@dell7480 ~]#
9) Show final format using parted.
[root@dell7480 ~]# parted -s /dev/sda print; Model: USB SanDisk 3.2Gen1 (scsi) Disk /dev/sda: 61.5GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 61.5GB 61.5GB msftdata [root@dell7480 ~]#
10) Use the system storage manager (ssm) to show the completed exFAT partition.
[root@dell7480 ~]# ssm list --------------------------------------------------------------------- Device Free Used Total Pool Mount point --------------------------------------------------------------------- /dev/nvme0n1 476.94 GB PARTITIONED /dev/nvme0n1p1 600.00 MB /boot/efi /dev/nvme0n1p2 1.00 GB /boot /dev/nvme0n1p3 465.33 GB 10.02 GB 475.35 GB dell7480 /dev/sda 57.30 GB PARTITIONED /dev/sda1 57.30 GB /dev/zram0 8.00 GB SWAP --------------------------------------------------------------------- --------------------------------------------------------- Pool Type Devices Free Used Total --------------------------------------------------------- dell7480 btrfs 1 467.30 GB 8.05 GB 475.35 GB --------------------------------------------------------- -------------------------------------------------------------------------------------- Volume Pool Volume size FS FS size Free Type Mount point -------------------------------------------------------------------------------------- dell7480 dell7480 475.35 GB btrfs 475.35 GB 467.30 GB btrfs dell7480:home dell7480 475.35 GB btrfs 475.35 GB 467.30 GB btrfs /home dell7480:root dell7480 475.35 GB btrfs 475.35 GB 467.30 GB btrfs / /dev/nvme0n1p1 600.00 MB vfat part /boot/efi /dev/nvme0n1p2 1.00 GB ext4 1.00 GB 677.35 MB part /boot /dev/sda1 57.30 GB exfat part -------------------------------------------------------------------------------------- [root@dell7480 ~]#
11) Just in case, always synchronize cached writes to persistent storage prior to removing the USB flash drive.
[root@dell7480 ~]# sync;sync; [root@dell7480 ~]#
