Inconsistency with Debian filesystem, shows no free space even when I have 145 GB space free

Question

I have a 200+GB HDD. I have set up Debian Squeeze 6 in following manner:

I have been seeing an error message saying I have run out of disk space. I used disk usage analyzer and I found that out of 225 GB only 80 GB is being used.

I have been using Ubuntu in dual boot mode where I used to just devote 10GB to whole Ubuntu system and mount Windows partitions in /media to save my data.

Answer 1

If you don't want to reorganize your partitions from scratch, I would:

1. resize your home partition to make 3GiB free space at the end using gparted
2. create a new partition on that free space
3. sudo mv /opt /root_opt
4. sudo mkdir /opt
5. add record to /etc/fstab to mount that new partition as /opt/
6. sudo mount -a
7. sudo mv /opt_root/* /opt/
8. sudo rmdir /opt

This way you will end up with ~ 80% of used space on /.

As an more risky alternative, you can boot from some LiceCD, and using gparted shrink your home partition by 4GiB from the beginning and extend your root partition at the end. But make backup first. It's bit more risky operation.

Also note, that unused disk space and available disk space is something else. For example if you create a new 100GiB partition with ext3 filesystem, then by default 5% is reserved to prevent fragmentation. So you will start with available < 95 GiB for non-root users without writing single file there. This is normal and this is good.

Answer 2

As far as I can tell, you gave all the disc space to /home. In / you don't have enough space left (or only 1.15 GB).
So you mounted root dir to the 10GB Partition and gave the rest to /home.

Thats the problem. How to fix this is I don't know. Didn't do linux for quite some time so I don't know what tools are there.

What you could do is: save your data, repartition and reinstall. I for myself don't do partitioning anymore if it is not really a must (this, for some, is more of a philosophical question).