Random reboot FreeNAS 11.1.U6

[EuropeanPassage]

Hi

I am experiencing unexpected reboot on FreeNAS 11.1.u6 its installed on Dell R710 has 2 CPU 48GB RAM and 2PSU. i have collected last 2 dumps /data/crash/, can some one please help on this
booting freeNAS from mirror USB device

this is the following error i get

Fatal trap 12: page fault while in kernel mode
cpuid = 7; apic id = 35
fault virtual address = 0x800018
fault code = supervisor read data, page not present
instruction pointer = 0x20:0xffffffff804864e0
stack pointer = 0x28:0xfffffe0fa66f9a70
frame pointer = 0x28:0xfffffe0fa66f9ad0
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 = 0 (zio_write_intr_1)

 

[dlavigne]

Were you able to determine the cause?

 

[EuropeanPassage]

Yes i think so,

it might be the USB drive i reinstall FreeNAS on other USB key and its been up for last 5 days
before it was mirror USB but i tried both the USB as striped but was failing