Hi, I have a system (not really a recent illumos kernel, probably around 2012) that recently caused a couple of core.fmd.xxx dumps, here's what mdb is saying:   bash-4.2# mdb core.fmd.1104 Loading modules: [ fmd libumem.so.1 libc.so.1 libnvpair.so.1 libtopo.so.1 libuut il.so.1 libavl.so.1 libsysevent.so.1 eft.so ld.so.1 ] $C fd98e988 libc.so.1`_lwp_kill+0x15(4, 6, 120a0, fef58000, fef58000, 4) fd98e9a8 libc.so.1`raise+0x2b(6, 0, fd98e9c0, feed83e9, 0, 0) fd98e9f8 libc.so.1`abort+0x10e(3a646d66, 4f424120, 203a5452, 75736e69, 63696666 , 746e6569) fd98ee18 fmd_panic(8080ec0, fd98ee44, 1, 0) fd98ee38 fmd_panic+0x12(8080ec0, c, 3e8, ffb3dd87) fd98ee78 fmd_alloc+0x81(c, 1, 1dca2110, 0, 893c688, 84fd718) fd98eeb8 fmd_eventq_insert_at_head+0x43(890bb48, 91ec5b8, 0, 92f1ab2d) fd98eed8 fmd_module_gc+0x66(893c680, 0, 0, fd98eef8) fd98ef18 fmd_modhash_apply+0x3e(84fd718, 8073d50, 0, 0, 6c275b0e, 30cef3) fd98ef48 fmd_gc+0x28(80998c0, d, ff19063b, 30ceff, 84f8a48) fd98efa8 fmd_timerq_exec+0x127(84f8a40, 0, feda22a0, fef58000) fd98efc8 fmd_thread_start+0x5b(826cfb8, 0, 0, 0) fd98efe8 libc.so.1`_thrp_setup+0x88(feda2240) fd98eff8 libc.so.1`_lwp_start(feda2240, 0, 0, 0, 0, 0)   Any idea?   Gabriele     Sonicle S.r.l.  :  http://www.sonicle.com Music:  http://www.gabrielebulfon.com Quantum Mechanics :  http://www.cdbaby.com/cd/gabrielebulfon