Question: I have a disk that is greater than 2TB
size. I cannot create a partition on this >2TB disk using fdisk. Can
you explain me with an example on how to create a partition on a disk
that is larger than 2TB using parted and GPT format?
Answer: If you are using fdisk to create partition on a >2TB disk, you’ll get the following warning message.
So, fdisk has created a partition of 2 TB as shown below (even though the disk size is around 6 TB).
Before creating the partition command, we should set the disk label to GPT.
GPT stands for GUID partition table format (GPT).
Use parted’s mklabel command to set disk label to GPT as shown below.
Just for curiosity, let us see how this >2TB partition is displayed in fdisk. As you see below, it still shows the size as roughly 2TB (under the Blocks columns). However there is a + at the end indicating that this is greater than 2TB. The System column displays “GPT”.
Answer: If you are using fdisk to create partition on a >2TB disk, you’ll get the following warning message.
# fdisk /dev/sdb Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) WARNING: The size of this disk is 5.9 TB (5908688535552 bytes). DOS partition table format can not be used on drives for volumes larger than (2199023255040 bytes) for 512-byte sectors. Use parted(1) and GUID partition table format (GPT).
Creating 2TB partition using Fdisk
The size of the disk in this example is roughly 6 TB. You can still create a partition in this disk for 2TB using fdisk as shown below.# fdisk /dev/sdb1 Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-718357, default 1): Using default value 1 Last cylinder, +cylinders or +size{K,M,G} (1-267349, default 267349): Using default value 267349As you see above, even though there are 718357 cylinders available on this disk (this is for total of roughly 6TB), the last cylinder value it shows is only 267349 (which is roughly close to 2TB in this example).
So, fdisk has created a partition of 2 TB as shown below (even though the disk size is around 6 TB).
Command (m for help): p Disk /dev/sdb: 5908.7 GB, 5908688535552 bytes 255 heads, 63 sectors/track, 718357 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x3dffd626 Device Boot Start End Blocks Id System /dev/sdb1 1 267349 2147480811 83 Linux
Set Partition Table to GPT using Parted mklabel
In our case, we need to create a partition >2TB. So, we should use parted command.Before creating the partition command, we should set the disk label to GPT.
GPT stands for GUID partition table format (GPT).
# parted /dev/sdb GNU Parted 2.1 Using /dev/sdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print Error: /dev/sdb: unrecognised disk label (parted) mklabel gpt (parted) print Model: Unknown (unknown) Disk /dev/sdb: 5909GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags
Create >2TB Partition using Parted mkpart
Use parted’s mkpart command as shown below to create partition that is greater than 2TB. In this example, we are creating a partition that is roughly of 6TB in size.# parted /dev/sdb (parted) mkpart primary 0GB 5909GB (parted) print Model: Unknown (unknown) Disk /dev/sdb: 5909GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 5909GB 5909GB primaryTo understand how to use parted command effectively, refer to: 9 Linux Parted Command Examples.
Just for curiosity, let us see how this >2TB partition is displayed in fdisk. As you see below, it still shows the size as roughly 2TB (under the Blocks columns). However there is a + at the end indicating that this is greater than 2TB. The System column displays “GPT”.
# fdisk /dev/sdb Command (m for help): print Disk /dev/sdb: 5908.7 GB, 5908688535552 bytes 255 heads, 63 sectors/track, 718357 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdb1 1 267350 2147483647+ ee GPT
Format and Mount the Partition
Use mkfs to format the partition. This will take some time depending the size of the partition. You’ll see that it is “Writing inode tables” and the counter will keep increasing. In this example, it roughly took around 15 minutes to complete the mkfs.# mkfs /dev/sdb1 mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 360644608 inodes, 1442550528 blocks 72127526 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 44024 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848, 512000000, 550731776, 644972544 Writing inode tables: 3955/44024 Writing inode tables: 5022/44024 Writing inode tables: 7218/44024 Writing inode tables: done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 23 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.Finally, mount this >2TB partition.
# mkdir /data # mount /dev/sdb1 /data # df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 127G 1.6G 119G 2% / /dev/sdb1 5.3T 59M 5.1T 1% /data
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