error message when starting smartd: FAILURE - SMART status=51 ...

[Steven Samuel Cole]

Hello,

I see an error message every time I boot my AMD64 FreeBSD 7.0 system or 
when I restart smartd. These are the dmesg lines that seem relevant to 
the issue (shortened for clarity):

kernel: FreeBSD 7.0-RELEASE #0: Fri Jun  6 22:06:44 NZST 2008
kernel: CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 5200+ (2611.86-MHz 
K8-class CPU)
kernel: Origin = "AuthenticAMD"  Id = 0x60fb2  Stepping = 2
kernel: usable memory = 8576704512 (8179 MB)
    ...
kernel: atapci2: <SiI SiI 3114 SATA150 controller> port 
0xd480-0xd487,0xd400-0xd403,0xd080-0xd087,0xd000-0xd003,0xcc00-0xcc0f 
mem 0xddeff400-0xddeff7ff irq 18 at device 10.0 on pci1
    ...
kernel: ata6: <ATA channel 0> on atapci2
kernel: ata7: <ATA channel 1> on atapci2
kernel: ata8: <ATA channel 2> on atapci2
kernel: ata9: <ATA channel 3> on atapci2
    ...
kernel: ad12: 476940MB <Seagate ST3500320AS SD15> at ata6-master SATA150
kernel: ad14: 476940MB <Seagate ST3500320AS SD15> at ata7-master SATA150
kernel: ad16: 476940MB <Seagate ST3500320AS SD15> at ata8-master SATA150
kernel: ad18: 476940MB <Seagate ST3500320AS SD15> at ata9-master SATA150

I am happy to provide more info if that helps.#
I am using the latest version of smartmontools (5.38).

The actual error messages are:

kernel: ad12: FAILURE - SMART status=51<READY,DSC,ERROR> error=4<ABORTED>
kernel: ad14: FAILURE - SMART status=51<READY,DSC,ERROR> error=4<ABORTED>
kernel: ad16: FAILURE - SMART status=51<READY,DSC,ERROR> error=4<ABORTED>
kernel: ad18: FAILURE - SMART status=51<READY,DSC,ERROR> error=4<ABORTED>

Apart from that, the disks seem to be working fine.
I am running a ZFS pool on them and they perform great, no worries 
whatsoever; I am simply unsure what these error messages mean and if 
they should worry me.

Also, the disks are SATA300, the controller supports SATA150 only; there 
is a jumper on the disks that limits them to SATA150 which I removed. 
Could that be relevant ?

Thank you very much for your attention.

Kind regards,

Steve