Bug 14779 - Disk space wastes a lot
Summary: Disk space wastes a lot
Status: CLOSED OBSOLETE
Alias: None
Product: File System
Classification: Unclassified
Component: btrfs (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: fs_btrfs@kernel-bugs.osdl.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-12-10 08:37 UTC by zhipeng.gong
Modified: 2012-06-18 14:37 UTC (History)
4 users (show)

See Also:
Kernel Version: 2.6.32.rc8
Subsystem:
Regression: No
Bisected commit-id:


Attachments

Description zhipeng.gong 2009-12-10 08:37:20 UTC
Run dd to fill up the disk, the command will run until it hits "No space left
on device", however a lot of disk space are still not used. It is not
reasonable for netbook with small SSD or embedded devices with NAND.

Reproduce Steps
===========================================================
(1)"df -h" shows the free size is 12G
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              14G  2.0G   12G  15% /

(2)dd if=/dev/zero of=tmpfile bs=1024 count=$(the free size of the disk)
dd: writing `tmpfile': No space left on device
8836158+0 records in
8836157+0 records out
9048224768 bytes (9.0 GB) copied, 677.506 s, 13.4 MB/s

(3)and then "df -h" shows 23% are still available, but you can't write any
bytes any more.
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              14G   11G  3.3G  77% /
Comment 1 Rolf Leggewie 2012-01-19 07:04:26 UTC
similar or probably the same issue are reported as

bug 16066
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/874684

I am experiencing the exact same issue in Ubuntu Lucid (Ubuntu Kernel and mainline kernel) as well as today's Debian Unstable.
Comment 2 Rolf Leggewie 2012-06-18 13:27:30 UTC
How about you ask if this is fixed instead of silently closing as OBSOLETE?
Comment 3 Alan 2012-06-18 14:17:51 UTC
How about because I couldn't make it break testing the example ?

Can you reproduce it ?
Comment 4 Rolf Leggewie 2012-06-18 14:36:28 UTC
well, as you can see above I was able to reproduce it in January, less than half a year ago.  I'm no longer using btrfs since it's so horribly broken, but I can test it once when I return to civilzation.
Comment 5 Rolf Leggewie 2012-06-18 14:37:50 UTC
bug 14779
bug 12555
bug 14113
bug 16066

(as taken from launchpad)

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