S-series PacketShapers running versions 11.2.1.9 and earlier may experience an issue where the PacketShaper process may restart repeatedly.
In the backtrace files, you'll see lines that look like this;
/opt/bluecoat/ps/bin/pshaper(readCacheData+0x105)[0x635595]
/opt/bluecoat/ps/bin/pshaper(readCacheBackupFile+0x2da)[0x63594a]
/opt/bluecoat/ps/bin/pshaper(urlCategoryCacheBackupDaemon+0x58)[0x635bf8]
The issue is caused by trying to read from and write to a corrupted URL cache.
This issue is resolved in 11.3.1.2 and later.