There is a file system and there isn't actually 20 GB of disk space in there.

df -k:

/dev/sdb1 20G 17G 1.9G 91% /var/tomcat

when I do a du -sh on /var/tomcat I only get:
du -sh
312M .

The file system keeps running out of space.
Does any one know whats happening?

vgscan:

Reading all physical volumes. This may take a while...
Found volume group "vg00" using metadata type lvm2


--- Volume group ---
VG Name vg00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 9
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 8
Open LV 8
Max PV 0
Cur PV 1
Act PV 1
VG Size 19.88 GB
PE Size 32.00 MB
Total PE 636
Alloc PE / Size 636 / 19.88 GB
Free PE / Size 0 / 0
VG UUID 2cAcZd-cvD4-3Wl2-tdNl-2Fkn-MqpB-7SFTtG

--- Physical volume ---
PV Name /dev/sda2
VG Name vg00
PV Size 19.89 GB / not usable 19.49 MB
Allocatable yes (but full)
PE Size (KByte) 32768
Total PE 636
Free PE 0
Allocated PE 636
PV UUID f7LuT2-MqJI-npun-uk4A-EdhK-Vna2-rj3bZK