Lesson 4.1: List, create, delete partitions on MBR and GPT disks

Partitions on a Disk

On a device, the type of the partition table determines the maximum number and size of individual partitions.

Maximum number of partitions:

On a device formatted with the Master Boot Record (MBR) partition table, you can have:

Up to four primary partitions.
Up to three primary partitions, one extended partition
- Multiple logical partitions within the extended partition

On a device formatted with the GUID Partition Table (GPT), you can have:

Up to 128 partitions, if using the parted utility.
- Though the GPT specification allows more partitions by increasing the reserved size of the partition table, the parted utility limits the area required for 128 partitions.

Partition Type	Maximum number of partitions	Maximum partition si
Master Boot Record (MBR)	4 primary, or 3 primary and 1 extended partition with 12 logical partitions	2TiB
GUID Partition Table (GPT)	128	8ZiB

FDISK

Creating a MBR-Based Disk Partitioning Structure using `fdisk`

[root@sanjeeb ~]# fdisk /dev/nvme0n2 
 
# Command to Print the drives
Command (m for help): p
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: dos
Disk identifier: 0x2797ea38
 
# Command to create partiton (Partition 1)
Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1): 
First sector (2048-10485759, default 2048): +1G
Value out of range.
First sector (2048-10485759, default 2048): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-10485759, default 10485759): +1G
Created a new partition 1 of type 'Linux' and of size 1 GiB.
 
# Command to create partiton (Partition 1)
Command (m for help): n
Partition type
   p   primary (1 primary, 0 extended, 3 free)
   e   extended (container for logical partitions)
Select (default p): 
Using default response p.
Partition number (2-4, default 2): 
First sector (2099200-10485759, default 2099200): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2099200-10485759, default 10485759): +512M
Created a new partition 2 of type 'Linux' and of size 512 MiB.
 
# Command to create partiton (Partition 1)
Command (m for help): n
Partition type
   p   primary (2 primary, 0 extended, 2 free)
   e   extended (container for logical partitions)
Select (default p): 
Using default response p.
Partition number (3,4, default 3): 
First sector (3147776-10485759, default 3147776): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (3147776-10485759, default 10485759): +200M
Created a new partition 3 of type 'Linux' and of size 200 MiB.
 
# Command to create partiton (Partition 1)
Command (m for help): n
Partition type
   p   primary (3 primary, 0 extended, 1 free)
   e   extended (container for logical partitions)
Select (default e): e
Selected partition 4
First sector (3557376-10485759, default 3557376): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (3557376-10485759, default 10485759): 
Created a new partition 4 of type 'Extended' and of size 3.3 GiB.
 
Command (m for help): p
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: dos
Disk identifier: 0x2797ea38
 
Device         Boot   Start      End Sectors  Size Id Type
/dev/nvme0n2p1         2048  2099199 2097152    1G 83 Linux     #(Partition 1)
/dev/nvme0n2p2      2099200  3147775 1048576  512M 83 Linux     #(Partition 2)
/dev/nvme0n2p3      3147776  3557375  409600  200M 83 Linux     #(Partition 3)
/dev/nvme0n2p4      3557376 10485759 6928384  3.3G  5 Extended  #(Partition 4)

Changing the partition type of Partition Number 2

Command (m for help): t
Partition number (1-4, default 4): 2
Hex code or alias (type L to list all): 82
Changed type of partition 'Linux' to 'Linux swap / Solaris'.
 
# Print the partitions 
Command (m for help): p
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: dos
Disk identifier: 0x2797ea38
 
Device         Boot   Start      End Sectors  Size Id Type
/dev/nvme0n2p1         2048  2099199 2097152    1G 83 Linux
/dev/nvme0n2p2      2099200  3147775 1048576  512M 82 Linux swap / Solaris    # Changed to 82 (SWAP)
/dev/nvme0n2p3      3147776  3557375  409600  200M 83 Linux
/dev/nvme0n2p4      3557376 10485759 6928384  3.3G  5 Extended

In the partitions printed below , nvme0n2p5 is the container for (nvme0n2p6, nvme0n2p7)

Device         Boot   Start      End Sectors  Size Id Type
/dev/nvme0n2p1         2048  4196351 4194304    2G 83 Linux     # Partition 1 (Primary)
/dev/nvme0n2p2      4196352  5220351 1024000  500M 83 Linux     # Partition 2 (Primary)
/dev/nvme0n2p3      5220352  6244351 1024000  500M 83 Linux     # Partition 3 (Primary)
/dev/nvme0n2p4      6244352 10485759 4241408    2G  5 Extended  # Partition 4 (Extended)
/dev/nvme0n2p5      6246400  6451199  204800  100M 83 Linux     # Partition 4-1 (Extended / Container)
/dev/nvme0n2p6      6453248  8296447 1843200  900M 83 Linux     # Partition 4-2 (Extended)
/dev/nvme0n2p7      8298496 10485759 2187264    1G 83 Linux     # Partition 4-3 (Extended)

Use the command w to save and exit.
Use the command q to unsave and quit.

To refresh `partprobe`

[root@sanjeeb ~]# partprobe /dev/nvme0n2

To delete all the partitions in a disk

[root@sanjeeb ~]# lsblk 
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sr0          11:0    1    8G  0 rom  /run/media/root/CentOS-Stream-9-BaseOS-aarch64
nvme0n1     259:0    0   20G  0 disk 
├─nvme0n1p1 259:1    0  600M  0 part /boot/efi
├─nvme0n1p2 259:2    0    1G  0 part /boot
└─nvme0n1p3 259:3    0 18.4G  0 part 
  ├─cs-root 253:0    0 16.4G  0 lvm  /
  └─cs-swap 253:1    0    2G  0 lvm  [SWAP]
nvme0n2     259:4    0    5G  0 disk 
├─nvme0n2p1 259:12   0    2G  0 part 
├─nvme0n2p2 259:13   0  500M  0 part 
├─nvme0n2p3 259:14   0  500M  0 part 
├─nvme0n2p4 259:15   0    1K  0 part 
├─nvme0n2p5 259:16   0  100M  0 part 
├─nvme0n2p6 259:17   0  900M  0 part 
└─nvme0n2p7 259:18   0    1G  0 part 
 
# Wiping off all the partitions of disk /dev/nvme0n2
[root@sanjeeb ~]# wipefs --all /dev/nvme0n2 
/dev/nvme0n2: 2 bytes were erased at offset 0x000001fe (dos): 55 aa
/dev/nvme0n2: calling ioctl to re-read partition table: Success
 
[root@sanjeeb ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sr0          11:0    1    8G  0 rom  /run/media/root/CentOS-Stream-9-BaseOS-aarch64
nvme0n1     259:0    0   20G  0 disk 
├─nvme0n1p1 259:1    0  600M  0 part /boot/efi
├─nvme0n1p2 259:2    0    1G  0 part /boot
└─nvme0n1p3 259:3    0 18.4G  0 part 
  ├─cs-root 253:0    0 16.4G  0 lvm  /
  └─cs-swap 253:1    0    2G  0 lvm  [SWAP]
nvme0n2     259:4    0    5G  0 disk

GDISK

Creating an GPT-Based Disk Partitioning Structure with `gdisk`

[root@server ~]# fdisk /dev/nvme0n2 
 
#Creating a new partition 
Command (m for help): n
Partition number (5-128, default 5): 
First sector (5425152-10485726, default 5425152): 
Last sector, +/-sectors or +/-size{K,M,G,T,P} (5425152-10485726, default 10485726): +50M
 
Created a new partition 5 of type Linux filesystem and of size 50 MiB.
 
# Viewing the partitions
Command (m for help): p
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: E0095413-4144-47C5-86A9-E1553AFD5F65
 
Device           Start     End Sectors  Size Type
/dev/nvme0n2p1    2048 2099199 2097152    1G Linux filesystem
/dev/nvme0n2p2 2099200 3123199 1024000  500M Linux filesystem
/dev/nvme0n2p3 3123200 5220351 2097152    1G Linux swap
/dev/nvme0n2p4 5220352 5425151  204800  100M Linux filesystem
/dev/nvme0n2p5 5425152 5527551  102400   50M Linux filesystem
 
# Save and Exit
Command (m for help): w
The partition table has been altered.
Syncing disks.
 
# Refreshing
[root@server ~]# partprobe /dev/nvme0n2
 
#Viewing the partitions 
[root@server ~]# lsblk 
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sr0          11:0    1 1024M  0 rom  
nvme0n1     259:0    0   20G  0 disk 
├─nvme0n1p1 259:1    0  600M  0 part /boot/efi
├─nvme0n1p2 259:2    0    1G  0 part /boot
└─nvme0n1p3 259:3    0 18.4G  0 part 
  ├─cs-root 253:0    0 16.4G  0 lvm  /
  └─cs-swap 253:1    0    2G  0 lvm  [SWAP]
nvme0n2     259:4    0    5G  0 disk 
├─nvme0n2p1 259:5    0    1G  0 part /data1
├─nvme0n2p2 259:6    0  500M  0 part /data2
├─nvme0n2p3 259:7    0    1G  0 part [SWAP]
├─nvme0n2p4 259:8    0  100M  0 part 
└─nvme0n2p5 259:9    0   50M  0 part

Formatting (Creating Filesystems)

mkfs -t <filesystem type> <partition name>

# To create a filesystem
[root@sanjeeb ~]# mkfs -t ext4 /dev/nvme0n2p2
mke2fs 1.46.5 (30-Dec-2021)
Creating filesystem with 307200 1k blocks and 76912 inodes
Filesystem UUID: f04e6fa2-ee3b-4d8c-922d-2accbb93892f
Superblock backups stored on blocks: 
	8193, 24577, 40961, 57345, 73729, 204801, 221185
 
Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done 
 
# To check filesystem 
[root@sanjeeb ~]# blkid /dev/nvme0n2p2 
/dev/nvme0n2p2: UUID="f04e6fa2-ee3b-4d8c-922d-2accbb93892f" TYPE="ext4" PARTLABEL="Linux swap" PARTUUID="889a041f-7012-4673-b70b-ffcc3cc3d4a6"
 
[root@sanjeeb ~]# blkid /dev/nvme0n2p1 
/dev/nvme0n2p1: UUID="399926fd-9ea0-4d14-92b0-8b579371f38e" TYPE="xfs" PARTLABEL="Linux filesystem" PARTUUID="a786964b-469f-491c-a0fd-7044d511f1bb"

Mounting

Temporary Mounting

Link with mount will be breaked if following this way :

# Mounting a Partition
[root@sanjeeb data1]# mount /dev/nvme0n2p1 /root/data1
[root@sanjeeb data1]# mount /dev/nvme0n2p2 /root/data2
 
[root@sanjeeb data1]# lsblk 
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sr0          11:0    1    8G  0 rom  /run/media/root/CentOS-Stream-9-BaseOS-aarch64
nvme0n1     259:0    0   20G  0 disk 
├─nvme0n1p1 259:1    0  600M  0 part /boot/efi
├─nvme0n1p2 259:2    0    1G  0 part /boot
└─nvme0n1p3 259:3    0 18.4G  0 part 
  ├─cs-root 253:0    0 16.4G  0 lvm  /
  └─cs-swap 253:1    0    2G  0 lvm  [SWAP]
nvme0n2     259:4    0    5G  0 disk 
├─nvme0n2p1 259:5    0    1G  0 part /root/data1    # Mounted
├─nvme0n2p2 259:6    0  300M  0 part /root/data2    # Mounted
└─nvme0n2p3 259:7    0  512M  0 part
 
# To check space utilized used df -h
# You wont be able to see data if it is unmounted, but will be stored at partition 
 
# Unmounting a Partition
[root@sanjeeb ~]# umount /dev/nvme0n2p1 
[root@sanjeeb ~]# umount /dev/nvme0n2p2

Permanent Mounting

File: /etc/fstab
Format: <partition name> <mount point> <fstype> <mount options> 0 0
Mount Options

Default	Non Default
rw	ro
exec	noexec
async	sync
suid	nosuid
dev	nodev
auto	noauto
nouser	user

# MOUNTING PARTITION nvme0n2p1 
# Add the command in fstab file 
[root@sanjeeb ~]# vim /etc/fstab 
/dev/nvme0n2p1          /root/data1             xfs     defaults        0       0
 
[root@sanjeeb ~]# systemctl daemon-reload 
[root@sanjeeb ~]# mount -a 
 
[root@sanjeeb ~]# lsblk 
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sr0          11:0    1    8G  0 rom  /run/media/root/CentOS-Stream-9-BaseOS-aarch64
nvme0n1     259:0    0   20G  0 disk 
├─nvme0n1p1 259:1    0  600M  0 part /boot/efi
├─nvme0n1p2 259:2    0    1G  0 part /boot
└─nvme0n1p3 259:3    0 18.4G  0 part 
  ├─cs-root 253:0    0 16.4G  0 lvm  /
  └─cs-swap 253:1    0    2G  0 lvm  [SWAP]
nvme0n2     259:4    0    5G  0 disk 
├─nvme0n2p1 259:5    0    1G  0 part /root/data1
├─nvme0n2p2 259:6    0  300M  0 part 
└─nvme0n2p3 259:7    0  512M  0 part 
 
[root@sanjeeb ~]# df -h 
Filesystem           Size  Used Avail Use% Mounted on
devtmpfs             4.0M     0  4.0M   0% /dev
tmpfs                1.8G     0  1.8G   0% /dev/shm
tmpfs                718M  9.3M  708M   2% /run
/dev/mapper/cs-root   17G   13G  3.4G  80% /
/dev/nvme0n1p2       960M  375M  586M  39% /boot
/dev/nvme0n1p1       599M  7.0M  592M   2% /boot/efi
tmpfs                359M  100K  359M   1% /run/user/0
/dev/sr0             8.1G  8.1G     0 100% /run/media/root/CentOS-Stream-9-BaseOS-aarch64
/dev/nvme0n2p1       960M   40M  921M   5% /root/data1
 
# MOUNTING PARTITION nvme0n2p2 
[root@sanjeeb ~]# vim /etc/fstab 
[root@sanjeeb ~]# tail -1 /etc/fstab 
/dev/nvme0n2p2 		/root/data2		ext4	defaults	0	0
 
[root@sanjeeb ~]# systemctl daemon-reload 
[root@sanjeeb ~]# mount -a 
 
[root@sanjeeb ~]# lsblk 
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sr0          11:0    1    8G  0 rom  /run/media/root/CentOS-Stream-9-BaseOS-aarch64
nvme0n1     259:0    0   20G  0 disk 
├─nvme0n1p1 259:1    0  600M  0 part /boot/efi
├─nvme0n1p2 259:2    0    1G  0 part /boot
└─nvme0n1p3 259:3    0 18.4G  0 part 
  ├─cs-root 253:0    0 16.4G  0 lvm  /
  └─cs-swap 253:1    0    2G  0 lvm  [SWAP]
nvme0n2     259:4    0    5G  0 disk 
├─nvme0n2p1 259:5    0    1G  0 part /root/data1
├─nvme0n2p2 259:6    0  300M  0 part /root/data2
└─nvme0n2p3 259:7    0  512M  0 part 
 
[root@sanjeeb ~]# df -h 
Filesystem           Size  Used Avail Use% Mounted on
devtmpfs             4.0M     0  4.0M   0% /dev
tmpfs                1.8G     0  1.8G   0% /dev/shm
tmpfs                718M  9.3M  708M   2% /run
/dev/mapper/cs-root   17G   13G  3.4G  80% /
/dev/nvme0n1p2       960M  375M  586M  39% /boot
/dev/nvme0n1p1       599M  7.0M  592M   2% /boot/efi
tmpfs                359M   96K  359M   1% /run/user/0
/dev/sr0             8.1G  8.1G     0 100% /run/media/root/CentOS-Stream-9-BaseOS-aarch64
/dev/nvme0n2p1       960M   40M  921M   5% /root/data1
/dev/nvme0n2p2       272M   14K  253M   1% /root/data2

Remounting a Partition

Command : mount -o remount,<new mount option> <mount point>

# TEMPORARY REMOUNTING 
# Providing ro , noexec mount options 
[root@sanjeeb ~]# mount -o remount,ro,noexec /root/data1 
 
[root@sanjeeb ~]# rm -rf * /root/data1 
rm: cannot remove 'data1/secure': Read-only file system
rm: cannot remove 'data1/secure-20240405': Read-only file system
rm: cannot remove 'data1/secure-20240407': Read-only file system
rm: cannot remove 'data1/secure-20240920': Read-only file system
...
 
[root@sanjeeb ~]# mount | grep data1 
/dev/nvme0n2p1 on /root/data1 type xfs (ro,noexec,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)
 
# PERMANENT REMOUNTING 
[root@sanjeeb ~]# mount | grep data2 
/dev/nvme0n2p2 on /root/data2 type ext4 (ro,nosuid,nodev,noexec,relatime,sync,seclabel)
 
[root@sanjeeb ~]# vim /etc/fstab 
[root@sanjeeb ~]# tail -1 /etc/fstab 
/dev/nvme0n2p2 		/root/data2		ext4	rw,exec,async,suid,dev,auto,nouser	0	0
 
[root@sanjeeb ~]# umount /root/data2 
[root@sanjeeb ~]# systemctl daemon-reload 
[root@sanjeeb ~]# mount /root/data2 
 
[root@sanjeeb ~]# mount | grep data2 
/dev/nvme0n2p2 on /root/data2 type ext4 (rw,relatime,seclabel)

Creating a GPT-Based and MBR-Based Partitioning with `parted`

[root@server ~]# parted /dev/nvme0n2
GNU Parted 3.5
Using /dev/nvme0n2
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mkpart                                                           
Partition type?  primary/extended? primary                                
File system type?  [ext2]?                                                
Start? 1MiB                                                               
End? 200MiB                                                               
(parted) p                                                                
Model: VMware Virtual NVMe Disk (nvme)
Disk /dev/nvme0n2: 5369MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
 
Number  Start   End    Size   Type     File system  Flags
 1      1049kB  210MB  209MB  primary  ext2

Viewing a GPT-Based Disk's Partition Table with `gdisk`

[root@server ~]# gdisk -l /dev/nvme0n2
GPT fdisk (gdisk) version 1.0.7
 
Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present
 
Found valid GPT with protective MBR; using GPT.
Disk /dev/nvme0n2: 10485760 sectors, 5.0 GiB
Model: VMware Virtual NVMe Disk
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): E0095413-4144-47C5-86A9-E1553AFD5F65
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 10485726
Partitions will be aligned on 2048-sector boundaries
Total free space is 4960189 sectors (2.4 GiB)
 
Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         2099199   1024.0 MiB  8300  Linux filesystem
   2         2099200         3123199   500.0 MiB   8300  Linux filesystem
   3         3123200         5220351   1024.0 MiB  8200  Linux swap
   4         5220352         5425151   100.0 MiB   8300  Linux filesystem
   5         5425152         5527551   50.0 MiB    8300

Viewing a Disk's Partition Table with `parted`

[root@server ~]# parted /dev/nvme0n2 
GNU Parted 3.5
Using /dev/nvme0n2
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p                                                                
Model: VMware Virtual NVMe Disk (nvme)
Disk /dev/nvme0n2: 5369MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
 
Number  Start   End    Size   Type     File system  Flags
 1      1049kB  210MB  209MB  primary  ext4

Deleting the GPT Based Partition with `gdisk`

[root@server ~]# gdisk /dev/nvme0n2
GPT fdisk (gdisk) version 1.0.7
 
Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present
 
Found valid GPT with protective MBR; using GPT.
 
Command (? for help): d
Partition number (1-5): 5
 
Command (? for help): p
Disk /dev/nvme0n2: 10485760 sectors, 5.0 GiB
Model: VMware Virtual NVMe Disk
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): E0095413-4144-47C5-86A9-E1553AFD5F65
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 10485726
Partitions will be aligned on 2048-sector boundaries
Total free space is 5062589 sectors (2.4 GiB)
 
Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         2099199   1024.0 MiB  8300  Linux filesystem
   2         2099200         3123199   500.0 MiB   8300  Linux filesystem
   3         3123200         5220351   1024.0 MiB  8200  Linux swap
   4         5220352         5425151   100.0 MiB   8300  Linux filesystem
 
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/nvme0n2.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot or after you
run partprobe(8) or kpartx(8)
The operation has completed successfully.

Deleting the Partition with `parted`

[root@server ~]# parted /dev/nvme0n2
GNU Parted 3.5
Using /dev/nvme0n2
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
Model: VMware Virtual NVMe Disk (nvme)
Disk /dev/nvme0n2: 5369MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
 
Number  Start   End    Size   Type     File system  Flags
 1      1049kB  210MB  209MB  primary  ext4
 
(parted) rm 1
(parted) p                                                                
Model: VMware Virtual NVMe Disk (nvme)
Disk /dev/nvme0n2: 5369MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
 
Number  Start  End  Size  Type  File system  Flags

Updating Disk Partition Information with `partprobe`

The command partprobe /dev/disk_name is used to inform the operating system kernel about changes to the partitions on a particular disk. When you add, remove, or modify partitions on a disk, the changes might not be immediately recognized by the operating system. By running partprobe, you're telling the system to re-read the partition table of the specified disk (/dev/disk_name) and update its records accordingly without requiring a system reboot. This is particularly useful in scenarios where you've made changes to disk partitions (e.g., creating, deleting, or resizing partitions) and need the system to recognize those changes without restarting.

[root@server ~]# partprobe /dev/nvme0n2

Updating the partition type with `gdisk`

[root@server ~]# gdisk /dev/nvme0n2 
GPT fdisk (gdisk) version 1.0.7
 
Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present
 
Found valid GPT with protective MBR; using GPT.
 
Command (? for help): p
Disk /dev/nvme0n2: 10485760 sectors, 5.0 GiB
Model: VMware Virtual NVMe Disk
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): E0095413-4144-47C5-86A9-E1553AFD5F65
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 10485726
Partitions will be aligned on 2048-sector boundaries
Total free space is 5062589 sectors (2.4 GiB)
 
Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         2099199   1024.0 MiB  8300  Linux filesystem
   2         2099200         3123199   500.0 MiB   8300  Linux filesystem
   3         3123200         5220351   1024.0 MiB  8200  Linux swap
   4         5220352         5425151   100.0 MiB   8300  Linux filesystem
 
Command (? for help): t
Partition number (1-4): 4
Current type is 8300 (Linux filesystem)
Hex code or GUID (L to show codes, Enter = 8300): L
Type search string, or <Enter> to show all codes: 
0700 Microsoft basic data                0701 Microsoft Storage Replica         
0702 ArcaOS Type 1                       0c01 Microsoft reserved                
2700 Windows RE                          3000 ONIE boot                         
3001 ONIE config                         3900 Plan 9                            
4100 PowerPC PReP boot                   4200 Windows LDM data                  
4201 Windows LDM metadata                4202 Windows Storage Spaces            
7501 IBM GPFS                            7f00 ChromeOS kernel                   
7f01 ChromeOS root                       7f02 ChromeOS reserved                 
8200 Linux swap                          8300 Linux filesystem                  
8301 Linux reserved                      8302 Linux /home                       
8303 Linux x86 root (/)                  8304 Linux x86-64 root (/)             
8305 Linux ARM64 root (/)                8306 Linux /srv                        
8307 Linux ARM32 root (/)                8308 Linux dm-crypt                    
8309 Linux LUKS                          830a Linux IA-64 root (/)              
830b Linux x86 root verity               830c Linux x86-64 root verity          
830d Linux ARM32 root verity             830e Linux ARM64 root verity           
830f Linux IA-64 root verity             8310 Linux /var                        
8311 Linux /var/tmp                      8312 Linux users home                 
8313 Linux x86 /usr                      8314 Linux x86-64 /usr                 
8315 Linux ARM32 /usr                    8316 Linux ARM64 /usr                  
8317 Linux IA-64 /usr                    8318 Linux x86 /usr verity             
Press the <Enter> key to see more codes, q to quit: q
 
Hex code or GUID (L to show codes, Enter = 8300): 8200
Changed type of partition to 'Linux swap'
 
Command (? for help): p
Disk /dev/nvme0n2: 10485760 sectors, 5.0 GiB
Model: VMware Virtual NVMe Disk
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): E0095413-4144-47C5-86A9-E1553AFD5F65
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 10485726
Partitions will be aligned on 2048-sector boundaries
Total free space is 5062589 sectors (2.4 GiB)
 
Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         2099199   1024.0 MiB  8300  Linux filesystem
   2         2099200         3123199   500.0 MiB   8300  Linux filesystem
   3         3123200         5220351   1024.0 MiB  8200  Linux swap
   4         5220352         5425151   100.0 MiB   8200  Linux swap
 
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/nvme0n2.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot or after you
run partprobe(8) or kpartx(8)
The operation has completed successfully.

Erasing all the disk inside a partition

wipefs --all /dev/disk_name

Viewing the partition table type

We can see that the below is in msdos || dos || MBR based

[root@server ~]# fdisk -l 
Disk /dev/nvme0n1: 20 GiB, 21474836480 bytes, 41943040 sectors
Disk model: VMware Virtual NVMe Disk
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: 028CCBBE-5452-4A7B-8FE9-542CBE517782
 
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 41940991 38612992 18.4G Linux LVM
 
 
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: dos     #This one is DOS based
Disk identifier: 0x6ca868d6
 
 
Disk /dev/nvme0n3: 6 GiB, 6442450944 bytes, 12582912 sectors
Disk model: VMware Virtual NVMe Disk
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
 
 
Disk /dev/mapper/cs-root: 16.41 GiB, 17620271104 bytes, 34414592 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
 
 
Disk /dev/mapper/cs-swap: 2 GiB, 2147483648 bytes, 4194304 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Changing the partition table type

Changing this partition table from MBR (Master Boot Record) to GPT(GUID Partition Table) using `gdisk`.

[root@server ~]# gdisk /dev/nvme0n2 
GPT fdisk (gdisk) version 1.0.7
 
Partition table scan:
  MBR: MBR only
  BSD: not present
  APM: not present
  GPT: not present
 
 
***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by
typing 'q' if you dont want to convert your MBR partitions
to GPT format!
***************************************************************
 
Command (? for help): w # Use w to save as gdisk automatically converts MBR to GPT
 
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/nvme0n2.
The operation has completed successfully.
 
[root@server ~]# fdisk -l /dev/nvme0n2 
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: 247AAE98-5819-43EA-9265-AA6BA3BB742A

Changing the partition table from GPT(GUID Partition Table) to MBR(Master Boot Record) using `parted`.

[root@server ~]# parted /dev/nvme0n2 
GNU Parted 3.5
Using /dev/nvme0n2
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel GPT
 
# Viewing the partition table type of /dev/nvme0n2
[root@server ~]# fdisk -l /dev/nvme0n2                                    
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: 47638739-9F59-48AC-8437-89F1A6F72239

Changing the partition table from MBR(Master Boot Record) to GPT(GUID Partition Table) using `parted`.

[root@server ~]# parted /dev/nvme0n2 
GNU Parted 3.5
Using /dev/nvme0n2
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel msdos         
 
# Viewing the partition table type of /dev/nvme0n2       
[root@server ~]# fdisk -l /dev/nvme0n2
Disk /dev/nvme0n2: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: VMware Virtual NVMe Disk
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: dos
Disk identifier: 0x4ebbff97

Lesson 4.1: List, create, delete partitions on MBR and GPT disks

Partitions on a Disk

Maximum number of partitions:

FDISK

Creating a MBR-Based Disk Partitioning Structure using fdisk

Changing the partition type of Partition Number 2

To refresh partprobe

To delete all the partitions in a disk

GDISK

Creating an GPT-Based Disk Partitioning Structure with gdisk

Formatting (Creating Filesystems)

Mounting

Temporary Mounting

Permanent Mounting

Remounting a Partition

Creating a GPT-Based and MBR-Based Partitioning with parted

Viewing a GPT-Based Disk's Partition Table with gdisk

Viewing a Disk's Partition Table with parted

Deleting the GPT Based Partition with gdisk

Deleting the Partition with parted

Updating Disk Partition Information with partprobe

Updating the partition type with gdisk