Create Partition and Mount | Temporary mount | Fuser command used | Creating a Swap Partition

 

HOW TO CREATE PARTITION AND MOUNT (FILE SYSTEM)

[root@dev ~]# fdisk /dev/sdb 

Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended

Partition number (1-4, default 1): 1
First sector (2048-16777215, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-16777215, default 16777215): +2048M   
Partition 1 of type Linux and of size 2 GiB is set

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

[root@dev ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)

Temporary mount
[root@dev ~]# mount /dev/sdb1 linux
[root@dev ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   60G  0 disk
├─sda1            8:1    0    1G  0 part
└─sda2            8:2    0   59G  0 part
  ├─centos-root 253:0    0   37G  0 lvm  /
  ├─centos-swap 253:1    0  3.9G  0 lvm  [SWAP]
  └─centos-home 253:2    0 18.1G  0 lvm  
sdb               8:16   0    8G  0 disk
└─sdb1            8:17   0    2G  0 part /root/linux

Fuser command used

[root@dev ~]# fuser -cu linux
/root/linux:         23963c(root)

Note :- It is show how many user used this directory  

[root@dev ~]# fuser  -ck linux
/root/linux:         23963c

Note :- forcefully kill user and log out 

To view the usage information of mounted partition:

[root@dev ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
devtmpfs                 1.9G     0  1.9G   0% /dev
tmpfs                    1.9G   34M  1.9G   2% /run
tmpfs                    1.9G     0  1.9G   0% /sys/fs/cgroup
/dev/mapper/centos-root   38G  4.6G   33G  13% /
/dev/sda1               1014M  149M  866M  15% /boot
/dev/mapper/centos-home   19G   33M   19G   1% /home
/dev/sdb1                2.0G  6.0M  1.8G   1% /root/linux

10. Creating a Swap Partition:

[root@dev ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): p

Disk /dev/sdb: 8589 MB, 8589934592 bytes, 16777216 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 label type: dos
Disk identifier: 0x13fe498e

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     4196351     2097152   83  Linux
/dev/sdb2         4196352     8390655     2097152   8e  Linux LVM

Command (m for help): n
Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): p
Partition number (3,4, default 3): 3
First sector (8390656-16777215, default 8390656):
Using default value 8390656
Last sector, +sectors or +size{K,M,G} (8390656-16777215, default 16777215): +2048M
Partition 3 of type Linux and of size 2 GiB is set

Command (m for help): p

Disk /dev/sdb: 8589 MB, 8589934592 bytes, 16777216 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 label type: dos
Disk identifier: 0x13fe498e

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     4196351     2097152   83  Linux
/dev/sdb2         4196352     8390655     2097152   8e  Linux LVM
/dev/sdb3         8390656    12584959     2097152   83  Linux

Command (m for help): t
Partition number (1-3, default 3): 3

Hex code (type L to list all codes): 82
Changed type of partition 'Linux' to 'Linux swap / Solaris'

Command (m for help): p

Disk /dev/sdb: 8589 MB, 8589934592 bytes, 16777216 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 label type: dos
Disk identifier: 0x13fe498e

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     4196351     2097152   83  Linux
/dev/sdb2         4196352     8390655     2097152   8e  Linux LVM
/dev/sdb3         8390656    12584959     2097152   82  Linux swap / Solaris

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

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@dev ~]# partprobe
[root@dev ~]# mkswap /dev/sdb3
Setting up swapspace version 1, size = 2097148 KiB
no label, UUID=d2fde43f-4e96-42a5-9ac8-8cb7fa6d18c5
[root@dev ~]# swapon /dev/sdb3
[root@dev ~]# swapon -s
Filename                Type        Size    Used    Priority
/dev/dm-1                                  partition    4063228    0    -2
/dev/sdb3                                  partition    2097148    0    -3
 

Check Swap memory 

[root@dev ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           3789         829         417          33        2542        2648
Swap:          6015           0        6015
 

Reduce Swap memory

[root@dev ~]# swapoff /dev/sdb3
[root@dev ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           3789         828         417          33        2542        2648
Swap:          3967           0        3967