See below:
root@jun% mount -t msdosfs /dev/da1s1 /mnt
mount_msdosfs: /dev/da1s1: Input/output error
-------------------------------------------------
nocd@jun> show system boot-messages
platform_early_bootinit: MX-PPC Series Early Boot Initialization
mxppc_set_re_type: hw.board.type is MX5-T
mxppc_set_re_type: REtype:126, model:mx5-t, model:MX5-T, i2cid:1366
WDOG initialized
Copyright (c) 1996-2014, Juniper Networks, Inc.
All rights reserved.
Copyright (c) 1992-2007 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
JUNOS 13.3R1.8 #0: 2014-04-09 20:16:29 UTC
builder@hallath.juniper.net:/volume/build/junos/13.3/release/13.3R1.8/obj-powerpc/junos/bsd/kernels/JUNIPER-PPC/kernel
WARNING: debug.mpsafenet forced to 0 as ipsec requires Giant
Timecounter "decrementer" frequency 66666666 Hz quality 0
cpu0: Freescale e500v2 core revision 3.0
cpu0: HID0 80004000<EMCP,TBEN>
real memory = 2118123520 (2020 MB)
avail memory = 2077224960 (1980 MB)
Security policy loaded: JUNOS MAC/pcap (mac_pcap)
Security policy loaded: JUNOS MAC/runasnonroot (mac_runasnonroot)
Security policy loaded: Junos MAC/veriexec (mac_veriexec)
MAC/veriexec fingerprint module loaded: SHA1
MAC/veriexec fingerprint module loaded: SHA256
ETHERNET SOCKET BRIDGE initialising
Initializing M/T/EX platform properties ..
nexus0: <Powerpc Nexus device>
ocpbus0: <on-chip peripheral bus> on nexus0
openpic0: <OpenPIC in on-chip peripheral bus> iomem 0xf7f40000-0xf7f600b3 on ocpbus0
uart0: <16550 or compatible> iomem 0xf7f04500-0xf7f0450f irq 58 on ocpbus0
uart0: console (9600,n,8,1)
uart1: <16550 or compatible> iomem 0xf7f04600-0xf7f0460f irq 58 on ocpbus0
lbc0: <Freescale Local Bus Controller> iomem 0xf7f05000-0xf7f05fff,0xf8000000-0xffffffff irq 20,21,22,24 on ocpbus0
cfi0: <AMD/Fujitsu - 8MB> iomem 0xff800000-0xffffffff on lbc0
tbbcpld0 iomem 0xff700000-0xff7fffff on lbc0
tbbcpld_attach: 1st IRQ alloc; start:4 end:4 flags:7
tbbcpld_attach: 2st IRQ alloc; start:6 end:6 flags:7
uart2: <16750 or compatible> iomem 0xff600000-0xff600007 on lbc0
uart3: <16750 or compatible> iomem 0xff500000-0xff500007 on lbc0
i2c0: <MPC85XX OnChip i2c Controller> iomem 0xf7f03000-0xf7f03014 irq 59 on ocpbus0
ds1672 rtc0: <DS1672 RTC> on i2c0
i2c1: <MPC85XX OnChip i2c Controller> iomem 0xf7f03100-0xf7f03114 irq 59 on ocpbus0
tsec0: <eTSEC ethernet controller> iomem 0xf7f24000-0xf7f24fff irq 45,46,50 on ocpbus0
tsec0: hardware MAC address 02:00:00:00:00:0b
miibus0: <MII bus> on tsec0
gentbi0: <Generic ten-bit interface> on miibus0
gentbi0: 1000baseSX-FDX, 1000baseT-FDX, auto
tsec1: <eTSEC ethernet controller> iomem 0xf7f25000-0xf7f25fff irq 51,52,56 on ocpbus0
tsec1: hardware MAC address 02:00:00:00:00:04
miibus1: <MII bus> on tsec1
gentbi1: <Generic ten-bit interface> on miibus1
gentbi1: 1000baseSX-FDX, 1000baseT-FDX, auto
tsec2: <eTSEC ethernet controller> iomem 0xf7f26000-0xf7f26fff irq 47,48,49 on ocpbus0
tsec2: hardware MAC address 54:4b:8c:30:d0:ff
miibus2: <MII bus> on tsec2
e1000phy0: <Marvell 88E1112 Gigabit PHY> on miibus2
e1000phy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseTX-FDX, auto
tsec3: <eTSEC ethernet controller> iomem 0xf7f27000-0xf7f27fff irq 53,54,55 on ocpbus0
tsec3: hardware MAC address 02:00:02:00:00:04
miibus3: <MII bus> on tsec3
gentbi2: <Generic ten-bit interface> on miibus3
gentbi2: 1000baseSX-FDX, 1000baseT-FDX, auto
pcib0: <Freescale MPC8572 PCI Express host controller> iomem 0xf7f09000-0xf7f09fff,0xe8000000-0xebffffff on ocpbus0
pci0: <PCI bus> on pcib0
pcib1: <PCI-PCI bridge> mem 0xe8000000-0xe80fffff at device 0.0 on pci0
pci1: <PCI bus> on pcib1
pcib2: <PCI-PCI bridge> mem 0xe8100000-0xe810ffff irq 0 at device 0.0 on pci1
pci2: <PCI bus> on pcib2
pci2: <serial bus, USB> at device 1.0 (no driver attached)
ehci0: <NEC uPD 72010x USB 2.0 controller> mem 0xe8200000-0xe82000ff irq 21 at device 1.1 on pci2
usb0: EHCI version 1.0
usb0: <NEC uPD 72010x USB 2.0 controller> on ehci0
usb0: USB revision 2.0
uhub0: NEC EHCI root hub, class 9/0, rev 2.00/1.00, addr 1
uhub0: 3 ports with 3 removable, self powered
umass0: ATP Electronics ATP IG eUSB, rev 2.00/11.00, addr 2
umass0: SCSI over Bulk-Only; quirks = 0x0000
umass0:0:0:-1: Attached to scbus0
umass1: ATP Electronics ATP IG eUSB, rev 2.00/11.00, addr 3
umass1: SCSI over Bulk-Only; quirks = 0x0000
umass1:1:1:-1: Attached to scbus1
umass2: USB USBFlashDrive, rev 2.00/1.00, addr 4
umass2: SCSI over Bulk-Only; quirks = 0x0000
umass2:2:2:-1: Attached to scbus2
Initializing product: 120 ..
Setting up M/T interface operations and attributes
platform_cookie_read not implemented
Initializing MX-PPC platform mastership..
Loading Redundant LT driver
###PCB Group initialized for udppcbgroup
###PCB Group initialized for tcppcbgroup
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <ATP ATP IG eUSB 1100> Fixed Direct Access SCSI-4 device
da0: 40.000MB/s transfers
da0: 3838MB (7860224 512 byte sectors: 255H 63S/T 489C)
da2 at umass-sim2 bus 2 target 0 lun 0
da2: <USBFlash USBFlashDrive 0100> Removable Direct Access SCSI-0 device
da2: 40.000MB/s transfers
da2: 3920MB (8028160 512 byte sectors: 255H 63S/T 499C)
da1 at umass-sim1 bus 1 target 0 lun 0
da1: <ATP ATP IG eUSB 1100> Fixed Direct Access SCSI-4 device
da1: 40.000MB/s transfers
da1: 3838MB (7860224 512 byte sectors: 255H 63S/T 489C)
Kernel thread "wkupdaemon" (pid 55) exited prematurely.
Trying to mount root from ufs:/dev/da2s1a
----------------------
nocd@jun> show version
Hostname: jun
Model: mx5-t
Junos: 13.3R1.8
JUNOS Base OS boot [13.3R1.8]
JUNOS Base OS Software Suite [13.3R1.8]
JUNOS Kernel Software Suite [13.3R1.8]
JUNOS Crypto Software Suite [13.3R1.8]
JUNOS Packet Forwarding Engine Support (MX80) [13.3R1.8]
JUNOS Online Documentation [13.3R1.8]
JUNOS Services Application Level Gateways [13.3R1.8]
JUNOS Services Jflow Container package [13.3R1.8]
JUNOS Services Stateful Firewall [13.3R1.8]
JUNOS Services NAT [13.3R1.8]
JUNOS Services RPM [13.3R1.8]
JUNOS Services Crypto [13.3R1.8]
JUNOS Services SSL [13.3R1.8]
JUNOS Services IPSec [13.3R1.8]
JUNOS Routing Software Suite [13.3R1.8]