Free disk space not appearing

gmartin · 02-03-2008, 02:30 PM

I managed to fill up my ext3 file system on my Slack12 (2.6.21.5smp) while backing up another computer. Ok, fine, I know what to do. So I went and deleted some old backup files. So far I've deleted 5-10GB of data but du still show the disk full.

Code:

root@USlack2:/tmp# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1            227029296 219870784         0 100%

I've forced an fsck to no avail. What am I doing wrong?

Alien Bob · 02-03-2008, 02:43 PM

An ext3-formatted partition reserves a percentage of the filesystem blocks for the super-user (root). This is a safeguard against a runaway process or a stupid user that manages to fill the disk to capacity. Even when the system reports 100% full, there will still be this percentage of hidden blocks available for writing by root.
Now, this percentage is 5 by default. For your 227 GB filesystem that amounts to roughly 11 GB of reserved space.

If you do not use this partition for the operating system or are not worried about the filesysten filling up completely, you can free (part of) these reserved blocks immediately. Use

Code:

tune2fs -m 0 /dev/sda1

to free up all of the reserved blocks.

Note that you can run this command on the mounted filesystem, and the effect will be immediate.

Eric

gmartin · 02-03-2008, 03:56 PM

Thanks for the help, Eric
I was able to free up more than 5% so I left the file system alone.

syg00 · 02-03-2008, 04:21 PM

Generally the "deleted" files are still open - reboot is a simple fix, or look at lsof.