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abbasi_ahsan
Asked: 2019-01-21 21:45:15 +0800 CST

how to access/use non-partition disk

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i am using Ubuntu 16.04 and want to access/use different disk in the server(following disks):

lsblk

NAME               MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                  8:0    0   372G  0 disk 
├─sda1               8:1    0   487M  0 part /boot
├─sda2               8:2    0     1K  0 part 
└─sda5               8:5    0 371.5G  0 part 
  ├─CR2--vg-root   252:0    0 115.6G  0 lvm  /
  └─CR2--vg-swap_1 252:1    0 255.9G  0 lvm  [SWAP]
sdb                  8:16   0  12.7T  0 disk 
└─sdb1               8:17   0  12.7T  0 part /mnt/storage
sdc                  8:32   0   5.5T  0 disk 
sdd                  8:48   0   5.5T  0 disk 
sde                  8:64   0   5.5T  0 disk 
sdf                  8:80   0   5.5T  0 disk 
sdg                  8:96   0   5.5T  0 disk 
sdh                  8:112  0   5.5T  0 disk 
sdi                  8:128  0   5.5T  0 disk 
sdj                  8:144  0   5.5T  0 disk 
sdk                  8:160  0   5.5T  0 disk 
sdl                  8:176  0   5.5T  0 disk 
sdm                  8:192  0   5.5T  0 disk 
sdn                  8:208  0   5.5T  0 disk 
sdo                  8:224  0   5.5T  0 disk 
sdp                  8:240  0   5.5T  0 disk 
sdq                 65:0    0   5.5T  0 disk 
sdr                 65:16   0   5.5T  0 disk 
sds                 65:32   0   5.5T  0 disk 
sdt                 65:48   0   5.5T  0 disk 
sdu                 65:64   0   5.5T  0 disk 
sdv                 65:80   0   5.5T  0 disk 
sdw                 65:96   0   5.5T  0 disk 
sdx                 65:112  0   5.5T  0 disk 
sdy                 65:128  0   5.5T  0 disk 
sdz                 65:144  0   5.5T  0 disk 
sr0                 11:0    1  1024M  0 rom  
nvme0n1            259:2    0   1.8T  0 disk 
nvme1n1            259:1    0   1.8T  0 disk 
nvme2n1            259:3    0   1.8T  0 disk 
nvme3n1            259:0    0   1.8T  0 disk

I can only access/use the following:

df -h 
Filesystem                Size  Used Avail Use% Mounted on
udev                      126G     0  126G   0% /dev
tmpfs                      26G   50M   26G   1% /run
/dev/mapper/CR2--vg-root  114G   83G   26G  77% /
tmpfs                     126G     0  126G   0% /dev/shm
tmpfs                     5.0M     0  5.0M   0% /run/lock
tmpfs                     126G     0  126G   0% /sys/fs/cgroup
/dev/sdb1                  13T   12T     0 100% /mnt/storage
/dev/sda1                 472M  159M  289M  36% /boot
tmpfs                      26G     0   26G   0% /run/user/1000

I also try follwoing :

sudo fdisk /dev/sdc

Welcome to fdisk (util-linux 2.27.1).
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.
The size of this disk is 5.5 TiB (6001175126016 bytes). DOS partition table format can not be used on drives for volumes larger than 2199023255040 bytes for 512-byte sectors. Use GUID partition table format (GPT).

Created a new DOS disklabel with disk identifier 0x2a4732aa.

How can i use other disks sdc, sdd, sdf ...

filesystem partitioning disk-usage hard-drive disk-management

3 Answers

  1. Best Answer

    You have the answer from Fdisk - MBR or DOS partitions can not be larger than 2TB. You need to change to GPT partitions.

    • 1

  2. You can make use of the additional disks by adding them to the file system table file /etc/fstab.

    But please note that you can only add disks that have file systems on them. Disks normally have a "partition table" that allows you to put multiple file systems on a single disk and Linux allows you to address such partitions in a partition table by adding a number after the SATA drive name - /dev/sda1 for the first partition in the drive /dev/sda (this is true for SATA drives and previously IDE drives, while for other drive technologies the kernel might use a more elaborate scheme - for example NVME drives use /dev/nvme<controller#>n<device#>p<partition#>).

    To use such disks in Linux you have to:

    1. Create the partition table - for example using fdisk as you've shown, but gdisk would probably be a better option as it supports natively GPT type partitions which are now the industry standard, or better yet: use the much more complete tool gparted. There are also graphical tools to do that, such as GNOME Disks or KDE partition manager.
    2. Create the file system you want on each of the partitions - if you use a graphical partitioning tool they will also help you with creating the file systems, otherwise you can use one of the mkfs programs such as mkfs.ext4.
    3. Add the new file system to your /etc/fstab (see the man page for details).

    But you are not required to use partitions if you don't want to and it doesn't make sense to - maybe because you only ever plan to have one file system per device. You can just create a file system directly on the "raw" device. For example to use /dev/sdc as a new file system mounted on /mnt/storage2, you can do:

    # mkfs.ext4 /dev/sdc
# echo '/dev/sdc /mnt/storage2 ext4 defaults 0 0' >> /etc/fstab
# mount -a

    (the second step should better be done with an actual text editor - cating stuff on top of a very important system file such as /etc/fstab is a horrible idea, this example is just so you understand what we are doing.)

    • 1

  3. I suggest create RAID on this drives, this way you will not have separate folder for mounting each drive, improve stability or speed. Its possible to just replace hard disk if it fail without loosing data with RAID. There are few raid types, read about them and decide which one suits your needs. From the first link you'll learn how to setup raid.

    RAID is a method of using multiple hard drives to act as one. There are two purposes of RAID:

    Expand drive capacity: RAID 0. If you have 2 x 500 GB HDD then total space become 1 TB.
Prevent data loss in case of drive failure: For example RAID 1, RAID 5, RAID 6, and RAID 10.

    ^ https://help.ubuntu.com/community/Installation/SoftwareRAID

    About RAID types: https://en.wikipedia.org/wiki/RAID#Standard_levels

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