Partition and format a new disk ext4

Posted on November 22, 2022  •  2 minutes  • 398 words  •  Suggest Changes

It’s a bit embarrassing that I still need to search for this, but here’s a guide on partitioning and formatting a new disk. Specifically, I’ll explain the process of formatting an SSD to serve as the /tmp directory on a server.

You can find the added disk, generally in the logs (syslog or messages).

# cat /var/log/syslog
Nov 22 15:14:05 server kernel: [13752487.699683] sd 0:0:9:0: [sdi] 3907029168 512-byte logical blocks: (2.00 TB/1.82 TiB)
Nov 22 15:14:05 server kernel: [13752487.700909] sd 0:0:9:0: [sdi] Write Protect is off
Nov 22 15:14:05 server kernel: [13752487.700914] sd 0:0:9:0: [sdi] Mode Sense: 9b 00 10 08
Nov 22 15:14:05 server kernel: [13752487.701705] sd 0:0:9:0: [sdi] Write cache: enabled, read cache: enabled, supports DPO and FUA
Nov 22 15:14:05 server kernel: [13752487.773737] sd 0:0:9:0: [sdi] Attached SCSI disk
Nov 22 15:17:52 server kernel: [13752714.826698]  sdi: sdi1

or if you recently added based on the date in /dev/sd*

brw-rw---- 1 root disk 8,   0 Aug 26 06:11 /dev/sda
brw-rw---- 1 root disk 8,   1 Aug 26 06:11 /dev/sda1
...
brw-rw---- 1 root disk 8, 128 Nov 22 15:17 /dev/sdi
brw-rw---- 1 root disk 8, 129 Nov 22 15:18 /dev/sdi1

Format the disk : (as root)

# fdisk -l /dev/sdi
n # for new partition
p # for primary
1 # (default) parition number
2048 # (default) start sector
3907029167 # (default) last sector
w # write changes to disk

format the disk in ext4 (for example)

# mkfs.ext4 /dev/sdi1 
mke2fs 1.45.5 (07-Jan-2020)
Discarding device blocks: done
Creating filesystem with 488378390 4k blocks and 122101760 inodes
Filesystem UUID: 6ed1591b-7e79-4b3f-934a-0fa26044212a
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 
        102400000, 214990848

Allocating group tables: done
Writing inode tables: done
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done

Then for mounting as /tmp (in this case), we can use /dev/sdi1 or much safer is using the UUID from the device. Since the UUID never changes. This can be done using blkid.

# blkid | grep sdi1
/dev/sdi1: UUID="6ed1591b-7e79-4b3f-934a-0fa26044212a" TYPE="ext4" PARTUUID="179fd4df-01"

You can also find this in /dev/disk/by-uuid/

Changing /etc/fstab

location, mountpoint, filetype, options, backup_operation (legacy), file system check order (0 : no, 1 : root, 2 : “other”)

/dev/disk/by-uuid/6ed1591b-7e79-4b3f-934a-0fa26044212a /tmp ext4 defaults   0   2

Then reboot the device or re-mount using :

mount -a

That’s how its done :)

img by lboccardo95