I have a big disk around 4.8 TB (RAID) and it has following partition (created by fdisk)

[root@server1 ~]# fdisk -l /dev/sde

WARNING: The size of this disk is 4.8 TB (4796404727808 bytes).
DOS partition table format can not be used on drives for volumes
larger than 2.2 TB (2199023255040 bytes). Use parted(1) and GUID
partition table format (GPT).

Disk /dev/sde: 4796.4 GB, 4796404727808 bytes
255 heads, 63 sectors/track, 583129 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1               1      267349  2147480811   83  Linux
/dev/sde2          267350      291665   195318270   83  Linux

I am trying to create 1 more partition but it is not picking the correct cylinder number, it is starting from 24316 instead of 291666, it looks like they are not in order. After a search with Google I found that I need to use the parted utility, but I don't know whether this issue is related to that or not so I need your suggestion

Command (m for help): p

Disk /dev/sde: 4796.4 GB, 4796404727808 bytes
255 heads, 63 sectors/track, 583129 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1               1      267349  2147480811   83  Linux
/dev/sde2          267350      291665   195318270   83  Linux

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
Partition number (1-4): 3
First cylinder (24316-583129, default 24316):
Using default value 24316
Sector 390630929 is already allocated
First cylinder (24316-583129, default 24316):
  • So you already have sde1 and sde2 and try to add now sde3 using parted? This won't change the partition table format to GPT, but you'll simply add another MSDOS format partition to the disk. You should wipe your disk completely and re-create your whole partition table as GPT. – Elias Probst Dec 5 '13 at 16:53
  • Yes i am trying to create new partition sde3 , but i never used parted before so just trying to find how to resolve this issue, is there any other way without touching current partition because it has data on it. – Satish Dec 5 '13 at 16:55
  • There's no way to solve this without touching the existing partitions. The existing partitions are created as MSDOS/MBR partitions, while anything beyond 2.2TB can only be addressed when using a GPT partition table. – Elias Probst Dec 5 '13 at 17:01
  • Then why fdisk allowed me to create two partition? 2TB? – Satish Dec 5 '13 at 17:04
  • Because they're withing the first 2.2TB of the disk. – Elias Probst Dec 5 '13 at 17:26

You can't use fdisk on disks larger than 2TB. This is a limitation of MBR style formatted disks. You have to use GPT - GUID Partitioning Table.

Take a look at the Arch Linux wiki on the topic: GUID Partition Table, for more information. Also I've found this article useful for explaining the differences between the 2 formats, titled: Windows GPT Disks – Is Bigger Really Better?.

What tools then?

Typically you'll use sgdisk to do the partitioning of GPT disks. You can read more about this tool here on its main project page.

Also thanks to one of the comments from @ewhacs, apparently you can convert MBR to GPT using sgdisk as well. It's covered on this page titled: Converting to or from GPT.


One of the more unusual features of gdisk is its ability to read an MBR partition table or BSD disklabel and convert it to GPT format without damaging the contents of the partitions on the disk. This feature exists to enable upgrading to GPT in case the limitations of MBRs or BSD disklabels become too onerous—for instance, if you want to add more OSes to a multi-boot configuration, but the OSes you want to add require too many primary partitions to fit on an MBR disk. (Unfortunately, though, many such OSes can't handle GPT.) I've heard from one user who used this ability to fix an over-2TiB RAID array that had been inappropriately partitioned with MBR. The BSD disklabel support can help simplify and extend a BSD partitioning scheme by removing the need to keep an MBR partition containing a BSD disklabel on the disk of a multi-boot computer.

In addition to converting to GPT format, GPT fdisk supports converting from GPT format to MBR format. This feature, though, comes with some caveats: Depending on how the disk was originally partitioned, it may not be possible to convert all the original partitions. Even if converting all the partitions is possible, there may be restrictions on which partitions can be turned into logical partitions, which may in turn result in some odd or undesirable assignments to primary vs. logical partitions in the final MBR partition table.

Note that the details of how to convert a disk, as well as the problems of a conversion, vary with the conversion type. You should read the appropriate section of this page to learn details. If you want to convert an MBR disk with a BSD disklabel partition, you'll have to perform both conversions.

However, I would make doubly sure to read through this documentation prior to attempting something like this. You might even want to setup a MBR formatted HDD prior and go through the process so you're as familiar with it as possible, before trying with live data!


  • Is there a way to fix this issue without loosing data? i meant just adjust cylinder using parted? because re-creating partition going to be pain in a** :( – Satish Dec 5 '13 at 17:14
  • No, as already stated above. You'll have to copy all data to another storage device and then recreate the whole partition based on GPT. You should have read the displayed warning regarding the 2.2TB limit when you initially created the first 2 partitions to avoid this situation. – Elias Probst Dec 5 '13 at 17:27
  • @Satish - the only way out of this without losing data is to do get a 2nd disk, move the existing data off of the RAID to it, re-partition & format the RAID, then move the data back. – slm Dec 5 '13 at 18:22
  • It's already labeled GPT, so he shouldn't lose any data. – jordanm Dec 5 '13 at 18:47
  • @jordanm what do you mean it is already labeled GPT? – Satish Dec 5 '13 at 19:54

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