No space left in lost+found

[bob prohaska]

Hi all,

Lately I've been seeing "sorry, no space left in lost+found directory" during
routine fsck of my rpi2. The messages seem to be new, in the last few weeks.
The machine has root on the microSD card, but /usr, /tmp, /var and swap are 
all on a mechanical USB hard disk. Unrecovered files/directories are in /tmp.

The running cycle is typically to build the latest revision of current, compile,
reboot, fsck -fy twice and run stress2 -a till it crashes. Next, reboot, run fsck -fy
three times, update using svnlite and repeat. 

After the reboot is complete, /lost+found is empty. 

Do I have something misconfigured?

Thanks for reading,

bob prohaska