On 9/21/2014 12:50, John R Pierce wrote: > every so often, I'm seeing these in my dmesg output, and I'm not sure > what they are? > > host[32625]: segfault at 0 ip 000000000040abb8 sp 00007ff59d36bd40 error > 4 in host[400000+1b000] > host[24560]: segfault at 0 ip 000000000040abb8 sp 00007f4fa1c4bd40 error > 4 in host[400000+1b000] > host[8354]: segfault at 0 ip 000000000040abb8 sp 00007fa07330dd40 error > 4 in host[400000+1b000] Normally the "in $foo" bit at the end names a program or library. I wonder if the host[$foo+$bar] syntax revers to a KVM guest? It's odd that it's correlated in time with some automatic software RAID check you've got going there. Is the order segfault-then-md as a closely-spaced pair, followed by a gap in time?