On 17/06/2014 9:40 p.m., Per Jessen wrote: > squid 2.7: > > Due to a kernel issue with ICMP redirects, my squid has been unused for > 5-6 months, but after having found the fix, it's now active again. > > I'm now seeing quite a few TCP_SWAPFAIL_MISS, which I believe to > mean "apparently cached, but cache not found" ? It's not IO error, so > what else might this be caused by? SWAPFAIL is I/O error or corrupted on-disk object. They come from disk corruption same as any other file corruption does. Also, from Squid shutting down before all client transactions are terminated (short shutdown_timeout, crash, manual "kill -9" execution / squid -k shutdown repeated twice, etc) If you have upgraded Squid to 3.2 or later release you may be seeing the recently improved object checksum and format detection identifying objects the older versions would just re-used (wrongly). Amos