Difference between ext2, ext3 and ext4 file system-
EXT-2
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EXT-3
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EXT-4
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Ext2 stands for second extended file system.
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Ext3 stands for third extended file system.
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Ext4 stands for fourth extended file system.
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It was introduced in 1993. Developed by Rémy Card.
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It was introduced in 2001. Developed by Stephen Tweedie.
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It was introduced in 2008.
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This was developed to overcome the limitation of the original ext file system.
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Starting from Linux Kernel 2.4.15 ext3 was available.
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Starting from Linux Kernel 2.6.19 ext4 was available.
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Ext2 does not have journaling feature.
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The main benefit of ext3 is that it allows journaling.
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Supports huge individual file size and overall file system size.
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Maximum individual file size can be from 16 GB to 2 TB
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Maximum individual file size can be from 16 GB to 2 TB
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Maximum individual file size can be from 16 GB to 16 TB
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Overall ext2 file system size can be from 2 TB to 32 TB
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Overall ext3 file system size can be from 2 TB to 32 TB
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Overall maximum ext4 file system size is 1 EB (exabyte). 1 EB = 1024 PB (petabyte). 1 PB = 1024 TB (terabyte).
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EXT2 to EXT3 and EXT3 to EXT4 Converting without data erase- Ext2 to ext3 file conversation
# tune2fs j /dev/sda5
Ext3 to ext4 file system conversation
# tune2fs O dir_index,uninit_bg,extents /dev/sda5
Ext2 to ext4 file system conversation
# tune2fs O dir_index,uninit_bg,has_journal /dev/sda5
Ext3 to ext2 file system back conversation
# tune2fs O ^has_journal /dev/sda5
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