Step 1: Discovery of Disks on a System
# Using List hardware to gather general information about disks
[root@server01 kim]# lshw -class disk -class storage -short
H/W path Device Class Description
=====================================================
/0/100/17 scsi1 storage Cannon Point-LP SATA Controller [AHCI Mode]
/0/100/17/0 /dev/sda disk 16GB KINGSTON SNS4151
/0/100/17/1 /dev/sdb disk 512GB Samsung SSD 850
# Listing blocks of storage
[root@server01 kim]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 14.9G 0 disk
├─sda1 8:1 0 4M 0 part
├─sda2 8:2 0 4G 0 part
├─sda3 8:3 0 7.5G 0 part
├─sda5 8:5 0 250M 0 part
├─sda6 8:6 0 250M 0 part
├─sda7 8:7 0 110M 0 part
├─sda8 8:8 0 286M 0 part
└─sda9 8:9 0 2.5G 0 part
sdb 8:16 0 477G 0 disk
├─sdb1 8:17 0 600M 0 part /boot/efi
├─sdb2 8:18 0 1G 0 part /boot
└─sdb3 8:19 0 475.4G 0 part
├─cl-root 253:0 0 50G 0 lvm /
├─cl-swap 253:1 0 15.7G 0 lvm [SWAP]
└─cl-home 253:2 0 409.6G 0 lvm /home
# Showing disk free (common cli command to display utilization)
[root@server01 kim]# df
Filesystem 1K-blocks Used Available Use% Mounted on
devtmpfs 16323804 0 16323804 0% /dev
tmpfs 16342180 0 16342180 0% /dev/shm
tmpfs 16342180 17248 16324932 1% /run
tmpfs 16342180 0 16342180 0% /sys/fs/cgroup
/dev/mapper/cl-root 52403200 3879908 48523292 8% /
/dev/mapper/cl-home 429313216 3027764 426285452 1% /home
/dev/sdb2 999320 176928 753580 20% /boot
/dev/sdb1 613184 6908 606276 2% /boot/efi
tmpfs 3268436 0 3268436 0% /run/user/0
overlay 52403200 3879908 48523292 8% /var/lib/docker/overlay2/b65c47ea3c25076b8addfaa1ec534911a74acffc0d9ad9a42a911672f02998d9/merged
tmpfs 3268436 0 3268436 0% /run/user/1000
overlay 52403200 3879908 48523292 8% /var/lib/docker/overlay2/87a24ea86dfc204e2c21e751dbe45405db38c429952f9b0188dd9b57d2918e61/merged
[root@server01 kim]# fdisk -l
Disk /dev/sda: 14.9 GiB, 16013942784 bytes, 31277232 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
Disklabel type: gpt
Disk identifier: 943BDACC-FCD6-5F43-8F21-04414CD0906D
--- Long output truncated ---
# Filtering result to show only disks information
[root@server01 kim]# fdisk -l | grep '^Disk'
Disk /dev/sda: 14.9 GiB, 16013942784 bytes, 31277232 sectors
Disklabel type: gpt
Disk identifier: 943BDACC-FCD6-5F43-8F21-04414CD0906D
Disk /dev/sdb: 477 GiB, 512110190592 bytes, 1000215216 sectors
Disklabel type: gpt
Disk identifier: 4167C3C8-E16D-4585-8E5C-510D8B55CBA1
Disk /dev/mapper/cl-root: 50 GiB, 53687091200 bytes, 104857600 sectors
Disk /dev/mapper/cl-swap: 15.7 GiB, 16886267904 bytes, 32980992 sectors
Disk /dev/mapper/cl-home: 409.6 GiB, 439831494656 bytes, 859045888 sectors
# Using another disk partitioning tool
[root@server01 kim]# parted -l
Model: ATA KINGSTON SNS4151 (scsi)
Disk /dev/sda: 16.0GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 32.8kB 4194kB 4162kB fat16 boot, esp
5 4211kB 266MB 262MB fat16 msftdata
6 266MB 528MB 262MB fat16 msftdata
7 528MB 644MB 115MB
8 644MB 944MB 300MB fat16 msftdata
9 944MB 3628MB 2684MB
2 3628MB 7922MB 4294MB fat16 msftdata
3 7922MB 16.0GB 8092MB
Model: ATA Samsung SSD 850 (scsi)
Disk /dev/sdb: 512GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 630MB 629MB fat32 EFI System Partition boot, esp
2 630MB 1704MB 1074MB ext4
3 1704MB 512GB 510GB lvm
Step 2: Make Changes to a Disk
# Partitioning a Disk
targetDisk='/dev/sda'
fdisk $targetDisk
# Showing partitions
Command (m for help): F
Unpartitioned space /dev/sda: 14.9 GiB, 16012877312 bytes, 31275151 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Start End Sectors Size
2048 31277198 31275151 14.9G
# Deleting partition
Command (m for help): d
Partition number (3,5-9, default 9): 1
Partition 1 has been deleted.
# Creating a partition
Command (m for help): n
Partition number (1-128, default 1):
First sector (34-31277198, default 2048): 34
Last sector, +sectors or +size{K,M,G,T,P} (34-31277198, default 31277198):
Created a new partition 1 of type 'Linux filesystem' and of size 14.9 GiB.
# Saving partition table changes
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
# Formatting a Disk
targetPartition='/dev/sda1'
mkfs.ext4 $targetPartition
[root@server01 kim]# mkfs.ext4 $targetPartition
mke2fs 1.44.6 (5-Mar-2019)
Discarding device blocks: done
Creating filesystem with 3909645 4k blocks and 979200 inodes
Filesystem UUID: 3cf16eda-8ded-4422-80e9-1e9f323c64fe
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208
Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
Step 3: modifying system memory using swap
# Creating a swap directory
diskName='/swap'
mkdir $diskName
mount $targetPartition $diskName
# Updating /etc/fstab file to create automount
echo "$targetPartition $diskName ext3 defaults 1 2" >> /etc/fstab
# Labeling the disk
e2label $targetPartition $diskName
# Allocating swapfile, setting appropriate permissions, creating swapfile
blockCount=$(df -P $targetPartition | tail -1 | awk '{print int($4/1024)}') # Obtain available disk space of
blockSize=1MiB
swapfile='/swap/swapfile'
sudo dd if=/dev/zero of=$swapfile bs=$blockSize count=$blockCount #allocate
chmod 600 $swapfile #secure the directory
mkswap $swapfile #make swapfile in the /swapfile directory
swapon $swapfile #configure system to use /swapfile
# Setting a swapfile to load on boot
echo "$swapfile none swap defaults 0 0" >> /etc/fstab
# Removing a swapfile
swapfileToRemove='/dev/mapper/cl-swap'
swapoff -v $swapfileToRemove
rm $swapfileToRemove -f
sed -i.bak '/\/dev\/mapper\/cl-swap/d' /etc/fstab # Assuming swapfile to remove is /dev/mapper/cl-swap
# Validation
[root@server01 kim]# swapon -s
Filename Type Size Used Priority
/swap/swapfile file 14487548 0 -2
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