run out of swap file number

I am running squid 2.2 STABLE2 at RedHat 5.2
squid stop with displaying this message

FATAL: You've run out of swap file numbers.

[cache@matis logs]# df
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/sda3 2190928 1990431 87239 96% /

squid was installed root file system. and 87239kbytes available.

why ? and how can I fix it ??
Received on Tue Jun 22 1999 - 20:03:19 MDT