I just upgraded a PIX 515e w/ 64MB RAM and 16MB flash from 6.3.4 to 7.2.2 and then to 8.0.3.
Here's the contents of my flash:
Directory of flash:/
3 d--- 384 09:16:26 Jan 30 2008 lost+found
7 -rw- 7280640 12:15:44 Jan 30 2008 pix803.bin
16128000 bytes total (4195328 bytes free)
I tried running "fsck" and it checks out fine. I'm trying to upload the ASDM file and "should" have enough space. The configuration is not long at all. Any ideas of what is taking up the extra supposedly empty space?