db:0:kdb.enter.default> bt
Tracing pid 348 tid 100193 td 0xfffff8000b866620
kdb_enter() at kdb_enter+0x3b/frame 0xfffffe010fbfd420
vpanic() at vpanic+0x19b/frame 0xfffffe010fbfd480
panic() at panic+0x43/frame 0xfffffe010fbfd4e0
trap_pfault() at trap_pfault/frame 0xfffffe010fbfd530
trap_pfault() at trap_pfault+0x49/frame 0xfffffe010fbfd590
trap() at trap+0x29d/frame 0xfffffe010fbfd6a0
calltrap() at calltrap+0x8/frame 0xfffffe010fbfd6a0
--- trap 0xc, rip = 0xffffffff8125815e, rsp = 0xfffffe010fbfd770, rbp = 0xfffffe010fbfd770 ---
copyout() at copyout+0x3e/frame 0xfffffe010fbfd770
uiomove_faultflag() at uiomove_faultflag+0xf4/frame 0xfffffe010fbfd7b0
pipe_read() at pipe_read+0x203/frame 0xfffffe010fbfd820
dofileread() at dofileread+0xba/frame 0xfffffe010fbfd860
kern_readv() at kern_readv+0x68/frame 0xfffffe010fbfd8b0
sys_read() at sys_read+0x84/frame 0xfffffe010fbfd900
amd64_syscall() at amd64_syscall+0xa86/frame 0xfffffe010fbfda30
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe010fbfda30
--- syscall (3, FreeBSD ELF64, sys_read), rip = 0x80096af4a, rsp = 0x7fffffffe728, rbp = 0x7fffffffe740 ---
Fatal trap 12: page fault while in kernel mode
cpuid = 2; apic id = 12
fault virtual address = 0x800e29000
fault code = supervisor write data, page not present
instruction pointer = 0x20:0xffffffff8125815e
stack pointer = 0x28:0xfffffe010fbfd770
frame pointer = 0x28:0xfffffe010fbfd770
code segment = base 0x0, limit 0xfffff, type 0x1b
= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags = interrupt enabled, resume, IOPL = 0
current process = 348 (logger)
trap number = 12
panic: page fault
cpuid = 2
KDB: enter: panic
Looks like a storage or filesystem problem to me. Reboot into single user mode and run fsck -y / no less than 5 times (until it neither finds problems or fixes problems), then reboot and see if it's better.
Though given the nature of the backtrace I'm more inclined to think it's a storage/disk failure or maybe disk controller/cable failure.