[CentOS] df -h shows system at 100% used, but there is space left

Wed Apr 29 14:43:17 UTC 2009
Tom Brown <tom at ng23.net>

>> Has anyone seen output like this before? Notice on my 
>> /dev/md0 That it reports 100% used, but also 5.3 Gb 
>> available. What would cause this?
>>
>>
>>
>> # df -h
>> Filesystem            Size  Used Avail Use% Mounted on
>> /dev/sda2              71G  1.6G   66G   3% /
>> /dev/sda1              99M   22M   73M  23% /boot
>> tmpfs                 506M     0  506M   0% /dev/shm
>> /dev/md0              903G  851G  5.3G 100% /home
>>     
>
> I've never run into the reserved blocks being an issue (even though it
> may be the case here). I have run out of inodes (one per file, and if
> you have a ton of little files...). Run df -i to see what percent inodes
> your using. 
>
> Wikipedia has a good explaination of inodes
> (http://en.wikipedia.org/wiki/Inode).
>   


sounds like reserved blocks to me also - use tune2fs to turn down the 
reserved blocks. That way you'll be able to use that space but be aware 
of the future problem that could cause you.