Linux File Systems: Ext2 vs Ext3 vs Ext4

Question 1

What does Ext2 stand for?

Answer 1

Second extended file system

Question 2

When was Ext2 introduced?

Answer 2

1993

Question 3

Who developed Ext2?

Answer 3

Rémy Card

Question 4

Why was Ext2 developed?

Answer 4

To overcome limitations of original ext file system

Question 5

Does Ext2 have journaling feature?

Answer 5

No

Question 6

What type of drives is Ext2 recommended for?

Answer 6

Flash drives, USB drives

Question 7

What is the maximum individual file size in Ext2?

Answer 7

16 GB to 2 TB

Question 8

What is the overall Ext2 file system size?

Answer 8

2 TB to 32 TB

Question 9

What does Ext3 stand for?

Answer 9

Third extended file system

Question 10

When was Ext3 introduced?

Answer 10

2001

Question 11

Who developed Ext3?

Answer 11

Stephen Tweedie

Question 12

Starting from which Linux Kernel was Ext3 available?

Answer 12

2.4.15

Question 13

What is the main benefit of Ext3?

Answer 13

Allows journaling

Question 14

What is journaling in Ext3?

Answer 14

A dedicated area to track changes, reduces potential file system corruption

Question 15

What is the maximum individual file size in Ext3?

Answer 15

16 GB to 2 TB

Question 16

What is the overall Ext3 file system size?

Answer 16

2 TB to 32 TB

Question 17

What are the three types of journaling available in Ext3?

Answer 17

Journal, Ordered, Writeback

Question 18

Can you convert an Ext2 file system to Ext3 directly?

Answer 18

Yes, without backup/restore

Question 19

What does Ext4 stand for?

Answer 19

Fourth extended file system

Question 20

When was Ext4 introduced?

Answer 20

2008

Question 21

Starting from which Linux Kernel was Ext4 available?

Answer 21

2.6.19

Question 22

What is the maximum individual file size in Ext4?

Answer 22

16 GB to 16 TB

Question 23

What is the overall maximum Ext4 file system size?

Answer 23

1 EB (exabyte)

Question 24

What are the new features introduced in ext4?

Answer 24

Multiblock allocation, delayed allocation, journal checksum, fast fsck, etc.

Question 25

What is the option available in ext4? (journaling)

Answer 25

Turning the journaling feature off.

Question 26

What command is used to create an ext2 file system?

Answer 26

mke2fs /dev/sda1

Question 27

What command is used to create an ext3 file system?

Answer 27

mkfs.ext3 /dev/sda1 or mke2fs -j /dev/sda1

Question 28

What command is used to create an ext4 file system?

Answer 28

mkfs.ext4 /dev/sda1 or mke2fs -t ext4 /dev/sda1

Question 29

How can you convert ext2 to ext3?

Answer 29

Unmount /dev/sda2, tune2fs -j /dev/sda2, mount /dev/sda2 /home

Question 30

How can you convert ext3 to ext4?

Answer 30

Unmount /dev/sda2, tune2fs -O extents,uninit_bg,dir_index /dev/sda2, e2fsck -pf /dev/sda2, mount /dev/sda2 /home

Question 31

ext4 Directory can contain a maximum of __________ subdirectories

Answer 31

64,000 subdirectories (as opposed to 32,000 in ext3)

Question 32

Journal (Types of journaling available in ext3 file system)

Answer 32

Metadata and content are saved in the journal.

Question 33

Ordered (Types of journaling available in ext3 file system)

Answer 33

Only metadata is saved in the journal. Metadata are journaled only after writing the content to disk. This is the default.

Question 34

Writeback (Types of journaling available in ext3 file system)

Answer 34

Only metadata is saved in the journal. Metadata might be journaled either before or after the content is written to the disk.