Strange Error -- Out of disk space?

This morning, I came in the office to find Squid looping trying to restart
itself. Looking in cache.log, I find the following entries,
repeated constantly as Squid tries to restart (see below).

Thing is...if I do a "df -k", both my cache directories still had 800 MB free
each...so why is Squid complaining that it has run out
of disk space?

In order to get it back up and running, I ended up blowing away the cache
directories and starting from scratch.

Thanks for any suggestions...
Rik

1999/07/14 07:21:06| Starting Squid Cache version 2.2.STABLE3 for
i386-pc-solari
s2.6...
1999/07/14 07:21:06| Process ID 13775
1999/07/14 07:21:06| With 1024 file descriptors available
1999/07/14 07:21:06| Performing DNS Tests...
1999/07/14 07:21:06| Successful DNS name lookup tests...
1999/07/14 07:21:06| helperOpenServers: Starting 10 'dnsserver' processes
1999/07/14 07:21:06| Unlinkd pipe opened on FD 16
1999/07/14 07:21:06| Swap maxSize 8192000 KB, estimated 630153 objects
1999/07/14 07:21:06| Target number of buckets: 12603
1999/07/14 07:21:06| Using 16384 Store buckets, replacement runs every 5
seconds
1999/07/14 07:21:06| Max Mem size: 131072 KB
1999/07/14 07:21:06| Max Swap size: 8192000 KB
1999/07/14 07:21:06| Rebuilding storage in Cache Dir #0 (DIRTY)
1999/07/14 07:21:06| Rebuilding storage in Cache Dir #1 (DIRTY)
1999/07/14 07:21:06| Set Current Directory to /usr/local/squid/cache
1999/07/14 07:21:06| Loaded Icons.
1999/07/14 07:21:06| Accepting HTTP connections on port 80, FD 41.
1999/07/14 07:21:06| Accepting ICP messages on port 3130, FD 42.
1999/07/14 07:21:06| Ready to serve requests.
1999/07/14 07:21:06| Configuring Parent weblock.cmis.abbott.com/80/7
1999/07/14 07:21:08| 65536 Entries read so far.
1999/07/14 07:21:10| 131072 Entries read so far.
1999/07/14 07:21:13| 196608 Entries read so far.
1999/07/14 07:21:15| 262144 Entries read so far.
1999/07/14 07:21:18| 327680 Entries read so far.
1999/07/14 07:21:21| 393216 Entries read so far.
1999/07/14 07:21:21| diskHandleWrite: FD 17: disk write error: (28) No space
lef
t on device
FATAL: Write failure -- check your disk space and cache.log
Squid Cache (Version 2.2.STABLE3): Terminated abnormally.
CPU Usage: 14.210 seconds
Maximum Resident Size: 0 KB
Page faults with physical i/o: 0
Memory usage for squid via mallinfo():
        total space in arena: 40705 KB
        Ordinary blocks: 2987 KB 1608 blks
        Small blocks: 37343 KB 797300 blks
        Holding blocks: 186 KB 7973 blks
        Free Small blocks: 127 KB
        Free Ordinary blocks: 61 KB
        Total in use: 40517 KB 100%
        Total free: 188 KB 0%
Received on Wed Jul 14 1999 - 06:54:42 MDT