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Ext keeps some reserved space so that if the disk is full a root user can login and still do stuff in the reserved space. However this value is quite large. If you have a modern disk then it can be many GB of space. As its default is 5% then for example on a 2TB disk that is approx 100GB of space reserved.

Normally I change it down to 2% from the default of 5%. The command would be (assuming the disk is /dev/sda2):

tune2fs -m 2 /dev/sda2

Then you can get some of the reserved space back :)

To check the current reserved space:

tune2fs -l /dev/sda2  | grep 'Reserved'

Compare the reserved block count prior and after running the change and it will be different. Unfortunately it does not display a %.

Run the commands with sudo if not root.

start/ext4secret.txt · Last modified: 2022/07/11 12:21 by peter