dmesg -M core after a long uptime.  unfortunately the kernel hanged
during the dump, necessitating a manual intervention, so the stack
gdb sees is not particularly useful in debugging this. -:(

	Sean.

/: got error 5 while accessing filesystem
panic: softdep_deallocate_dependencies: unrecovered I/O error
Begin traceback...
softdep_deallocate_dependencies(c68e8a70,c68e8a70,c0250920,a4) at softdep_deallocate_dependencies+0x43
brelse(c68e8a70,c0bcbd50,c0250920,a4,2fff581b) at brelse+0x199
biodone(c68e8a70,1,d5c58740,d6dde1c8,0) at biodone+0x95
scsipi_done(c0bcbd50,c09c2488,d6d36eb0,c0107ded,c099f400,c0bcbd50,c099f400,0) at scsipi_done+0x165
ahc_done(c099f400,c09c2488,1,0,c09c2488) at ahc_done+0x342
ahc_abort_scbs(c099f400,6,41,0,ff,1,4,af15d) at ahc_abort_scbs+0x2fb
ahc_handle_scsiint(c099f400,4,d6d36fa0,c01f8002,c099c8e0) at ahc_handle_scsiint+0x920
ahc_intr(c099f400) at ahc_intr+0x1a5
Xintr15() at Xintr15+0x70
--- interrupt ---
   0x1014c:
End traceback...
syncing disks... ahc2: ahc_intr - referenced scb not valid during SELTO scb(255, 153)
panic: ahc2: brkadrint, Scratch or SCB Memory Parity Error at seqaddr = 0x0

Begin traceback...
ahc_intr(c099f400,0,d6d36aa0,c0134fd0) at ahc_intr+0x184
ahc_timeout(c09c2488,d64aba38,1,c0000010) at ahc_timeout+0x37
softclock(1,d64aba54,c000a7e4,c0143e08,0) at softclock+0x106
Xsoftclock() at Xsoftclock+0xf
--- interrupt ---
sdstrategy+0x15b:
End traceback...

dumping to dev 4,1 offset 500575
...