Editing Mkfs.ext4

* Man page <code>mkfs.ext4</code>: https://linux.die.net/man/8/mkfs.ext4
* Man page <code>[[ext4]]</code>: https://man7.org/linux/man-pages/man5/ext4.5.html

<pre>
mkfs.ext4 /dev/vg01/lv01
mke2fs 1.44.1 (24-Mar-2018)
Creating filesystem with 2441850880 4k blocks and 305233920 inodes
Filesystem UUID: e6742357-a181-4b82-837f-9a01f3e52568
Superblock backups stored on blocks:
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
	4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
	102400000, 214990848, 512000000, 550731776, 644972544, 1934917632

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

 [[mkfs.ext4]] /dev/sda222
 mke2fs 1.44.1 (24-Mar-2018)
 Found a dos partition table in /dev/sda222
 Proceed anyway? (y,N) y
 mkfs.ext4: inode_size (128) * inodes_count (0) too big for a filesystem with 0 blocks, specify higher inode_ratio (-i) or lower inode count (-N).
 
 Review your partition table (<code>[[fdisk -l]] /dev/sda222</code>), read https://www.beinfog.com/systems/dont-try-to-create-file-system-on-an-extended-partition/


 mkfs.ext4 -S
 -S  Write [[superblock]] and group descriptors only.


Create an ext4 filesystem on a file <ref>https://askubuntu.com/a/841306</ref>: 
 [[fallocate]] -l 1G  /path/to/yourfile
 mkfs.ext4 -F /path/to/yourfile
 -F force mke2fs to create a filesystem, even if the specified device is not a partition on a block special device, or if other parameters do not make sense. In order to force mke2fs to create a filesystem even if the filesystem appears to be in use or is mounted (a truly dangerous thing to do), this option must be specified twice. (from man page)
 sudo [[mount]] /path/to/yourfile /mnt/directory_to_mount

== Activities ==
# Create an [[ext4]] filesystem using <code>[[mkfs.ext4]]</code> command
# Learn about bytes per [[inode]] ratio: https://wiki.archlinux.org/index.php/ext4#Bytes-per-inode_ratio
# [[resize2fs]] online and ext4 filesystem
# Learn about Lazy initialization feature of ext4: https://www.thomas-krenn.com/en/wiki/Ext4_Filesystem#Lazy_Initialization and how to avoid it <code>mkfs.ext4 -E lazy_itable_init=0,lazy_journal_init=0 /dev/mapper/fc-device</code>


== Related commands ==
* <code>[[mount]]</code>

== See also ==
* {{filesystems}}
* {{ext4}}
* [[mount]] (/etc/[[fstab]])
* {{mkfs}}
* {{lvm commands}}
* [[inode]], [[superblock]] and [[block]] size

[[Category:Linux]]
[[Category:Storage]]
@@ Line 36: / Line 36: @@
   -F force mke2fs to create a filesystem, even if the specified device is not a partition on a block special device, or if other parameters do not make sense. In order to force mke2fs to create a filesystem even if the filesystem appears to be in use or is mounted (a truly dangerous thing to do), this option must be specified twice. (from man page)
   sudo [[mount]] /path/to/yourfile /mnt/directory_to_mount
- [[df -h]] /mnt/directory_to_mount
 == Activities ==