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I recently installed Arch Linux on an Intel 40GB SSD. I used GPT for partioning (via GNU parted) and created the following partions:

  • /dev/sda1 : 1 MB, no FS, flag=bios_grub
  • /dev/sda2 : 30MB, /boot, ext2, flag=boot
  • /dev/sda3 : 20GB, /home, ext4
  • /dev/sda4 : ~20GB, /, ext4

After struggling to install grub2 from the livecd environment (which I finally did via grub-install /dev/sda --root-directory=/mnt/ --no-floppy --force) I got a working system.

However, when I was inspecting disk usage with df I noticed that my home partition had around 170MB of used space on it. This surprised me because the only things on /home were one users .bashrc, .bash_history, and .lesshst. du confirmed that there was only a few KB of space being used on /home.

Why does df report approximately 170MB being used when du does not? Is this space "gone forever", or can I regain it by repartioning and/or reinstalling?

When I installed grub2 it said something along the lines of "your embed area is too small", and that I could "use BLOCKLISTS, but BLOCKLISTS are UNRELIABLE". In the end the only way I could get a system booting from the SSD was to use blocklists via the grub-install --force flag. Is this related to the mysterious missing 170MB?


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up vote 1 down vote accepted

Assuming you are using ext3/4, the journal uses 128 MB iirc. The remaining 42 MB is probably the resize inode.

If you got "your embed area is too small" it is because grub could not find the bios boot partition.

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Thank you, that seems to make sense (I am using ext4). Out of interest, what is the "resize inode" used for? A quick google doesn't reveal much information (beyond other peoples problems). – pisswillis Jan 13 '11 at 14:59
It reserves space to expand the group descriptor table so you can expand the fs later. – psusi Jan 13 '11 at 18:09

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