Hackathon - Linux

Mastering Linux

View the Project on GitHub ricmmartins/fasthack-linux

Challenge 09 - Disks, partitions and file systems - Coach’s Guide

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Notes & Guidance

  1. Identify the new disk added to the machine

student@vm01:~$ sudo fdisk -l | grep "^Disk"

Disk /dev/loop0: 43.64 MiB, 45748224 bytes, 89352 sectors
Disk /dev/loop1: 61.92 MiB, 64901120 bytes, 126760 sectors
Disk /dev/loop2: 67.83 MiB, 71106560 bytes, 138880 sectors
Disk /dev/sda: 30 GiB, 32213303296 bytes, 62916608 sectors
Disk model: Virtual Disk
Disklabel type: gpt
Disk identifier: D9AF7253-EE93-498D-B696-43092C65B2DD
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 sectors
Disk model: Virtual Disk
Disklabel type: dos
Disk identifier: 0x4e60c282
Disk /dev/sdc: 5 GiB, 5368709120 bytes, 10485760 sectors
Disk model: Virtual Disk

student@vm01:~$ sudo dmesg | grep sdc

[  150.665009] sd 1:0:0:0: [sdc] 10485760 512-byte logical blocks: (5.37 GB/5.00 GiB)
[  150.665012] sd 1:0:0:0: [sdc] 4096-byte physical blocks
[  150.665235] sd 1:0:0:0: [sdc] Write Protect is off
[  150.665237] sd 1:0:0:0: [sdc] Mode Sense: 0f 00 10 00
[  150.666843] sd 1:0:0:0: [sdc] Write cache: disabled, read cache: enabled, supports DPO and FUA
[  150.694433] sd 1:0:0:0: [sdc] Attached SCSI disk

  1. Edit the disk partition table:

    student@vm01:~$ sudo fdisk /dev/sdc

    1. Add a new partition with 500MB
     Welcome to fdisk (util-linux 2.34).
 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 0x29026b65.

 Command (m for help): n
 Partition type
     p   primary (0 primary, 0 extended, 4 free)
     e   extended (container for logical partitions)
 Select (default p): p
 Partition number (1-4, default 1): 1
 First sector (2048-10485759, default 2048):
 Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-10485759, default 10485759): +500M

 Created a new partition 1 of type 'Linux' and of size 500 MiB.

 Command (m for help): w
 The partition table has been altered.
 Calling ioctl() to re-read partition table.
 Syncing disks.
    1. List and identify in the S.O. the partition created

    student@vm01:~$ ls -l /dev/sdc*

     brw-rw---- 1 root disk 8, 32 Apr  6 15:09 /dev/sdc
 brw-rw---- 1 root disk 8, 33 Apr  6 15:09 /dev/sdc1
    1. Erase partition

    student@vm01:~$ sudo fdisk /dev/sdc

     Welcome to fdisk (util-linux 2.34).
 Changes will remain in memory only, until you decide to write them.
 Be careful before using the write command.


 Command (m for help): d
 Selected partition 1
 Partition 1 has been deleted.

 Command (m for help): w
 The partition table has been altered.
 Calling ioctl() to re-read partition table.
 Syncing disks.
    1. Check in S.O. that the partition has been removed

    student@vm01:~$ ls -l /dev/sdc*

     brw-rw---- 1 root disk 8, 32 Apr  6 15:12 /dev/sdc
    1. Add two new partitions with a native Linux partition (83), one with 500MB and another with 100MB

    student@vm01:~$ sudo fdisk /dev/sdc

     Welcome to fdisk (util-linux 2.34).
 Changes will remain in memory only, until you decide to write them.
 Be careful before using the write command.


 Command (m for help): n
 Partition type
     p   primary (0 primary, 0 extended, 4 free)
     e   extended (container for logical partitions)
 Select (default p): p
 Partition number (1-4, default 1): 1
 First sector (2048-10485759, default 2048):
 Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-10485759, default 10485759): +500M

 Created a new partition 1 of type 'Linux' and of size 500 MiB.

 Command (m for help): n
 Partition type
     p   primary (1 primary, 0 extended, 3 free)
     e   extended (container for logical partitions)
 Select (default p): p
 Partition number (2-4, default 2):
 First sector (1026048-10485759, default 1026048):
 Last sector, +/-sectors or +/-size{K,M,G,T,P} (1026048-10485759, default 10485759): +100M
    
 Created a new partition 2 of type 'Linux' and of size 100 MiB.

 Command (m for help): w
 The partition table has been altered.
 Calling ioctl() to re-read partition table.
 Syncing disks.
    1. Check in S.O. that the partitions were created

    student@vm01:~$ ls -l /dev/sdc*

     brw-rw---- 1 root disk 8, 32 Apr  6 15:53 /dev/sdc
 brw-rw---- 1 root disk 8, 33 Apr  6 15:53 /dev/sdc1
 brw-rw---- 1 root disk 8, 34 Apr  6 15:53 /dev/sdc2

  2. Create a file system on each of the partitions created

student@vm01:~$ sudo mkfs.ext4 /dev/sdc1

mke2fs 1.45.5 (07-Jan-2020)
Discarding device blocks: done
Creating filesystem with 128000 4k blocks and 128000 inodes
Filesystem UUID: 789bd630-3dc8-4356-9bd5-d96f3172f1d1
Superblock backups stored on blocks:
    32768, 98304

Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

student@vm01:~$ sudo mkfs.ext4 /dev/sdc2

mke2fs 1.45.5 (07-Jan-2020)
Discarding device blocks: done
Creating filesystem with 25600 4k blocks and 25600 inodes

Allocating group tables: done
Writing inode tables: done
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done
  1. Create a directory for each of the partitions inside the /mnt directory

student@vm01:~$ sudo mkdir /mnt/dir1

student@vm01:~$ sudo mkdir /mnt/dir2

  1. Mount each of the partitions in the respective directory

student@vm01:~$ sudo mount /dev/sdc1 /mnt/dir1

student@vm01:~$ sudo mount /dev/sdc2 /mnt/di2

  1. Verify that the partitions are mounted correctly in OS.

student@vm01:~$ sudo ls -l /mnt/dir*

/mnt/dir1:
total 16
drwx------ 2 root root 16384 Apr  6 15:59 lost+found

/mnt/dir2:
total 16
drwx------ 2 root root 16384 Apr  6 15:59 lost+found
  1. Write files inside one of the partitions

student@vm01:~$ sudo touch /mnt/dir1/file1

student@vm01:~$ sudo touch /mnt/dir2/file1

student@vm01:~$ sudo ls -l /mnt/dir*

/mnt/dir1:
total 16
-rw-r--r-- 1 root root     0 Apr  6 16:13 file1
drwx------ 2 root root 16384 Apr  6 15:59 lost+found

/mnt/dir2:
total 16
-rw-r--r-- 1 root root     0 Apr  6 16:13 file1
drwx------ 2 root root 16384 Apr  6 15:59 lost+found
  1. Unmount the partitions

student@vm01:~$ sudo umount /mnt/dir1

student@vm01:~$ sudo umount /mnt/dir2

  1. Remove existing partitions

student@vm01:~$ sudo fdisk /dev/sdc

Welcome to fdisk (util-linux 2.34).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Command (m for help): d
Partition number (1,2, default 2): 1

Partition 1 has been deleted.

Command (m for help): d
Selected partition 2
Partition 2 has been deleted.

Command (m for help): w
The partition table has been altered.

The kernel still uses the old partitions. The new table will be used at the next reboot.
Syncing disks.