SMART 193 LOAD_CYCLE_COUNT

[FreeNASBob]

I have some Toshiba laptop drives running on an Asrock 2550D4I with 16GB ECC RAM that are giving me insane load_cycle_counts. I have disabled APM in BIOS and set APM on the drives in FreeNAS to level 254. I even tried camcontrol to disable APM in the disk itself and the disk reports that APM is disabled, but I'm still seeing the load_cycle_count increase by about 50 per hour with nobody accessing FreeNAS at all. At this rate they'll reach their rated 600,000 cycles in 500 days.

I can't seem to find any utilities that would disable head parking in the drive itseld, but ataidle and camcontrol have been unsuccessful. If anyone has any ideas that would be great.

 

[FreeNASBob]

The odd thing is that the drive shows APM disabled.

Code:

[root@freenas] ~# camcontrol identify /dev/ada0

pass0: <TOSHIBA MQ01ABB200 AY000U> ATA-8 SATA 2.x device
pass0: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)

protocol              ATA/ATAPI-8 SATA 2.x
device model          TOSHIBA MQ01ABB200
firmware revision     AY000U
serial number         34LLPLFST
WWN                   5000039562b857d8
cylinders             16383
heads                 16
sectors/track         63
sector size           logical 512, physical 4096, offset 0
LBA supported         268435455 sectors
LBA48 supported       3907029168 sectors
PIO supported         PIO4
DMA supported         WDMA2 UDMA5 
media RPM             5400

Feature                      Support  Enabled   Value           Vendor
read ahead                     yes	yes
write cache                    yes	yes
flush cache                    yes	yes
overlap                        no
Tagged Command Queuing (TCQ)   no	no
Native Command Queuing (NCQ)   yes		32 tags
SMART                          yes	yes
microcode download             yes	yes
security                       yes	no
power management               yes	no
advanced power management      yes	no	128/0x80
automatic acoustic management  no	no
media status notification      no	no
power-up in Standby            no	no
write-read-verify              no	no
unload                         yes	yes
free-fall                      no	no
Data Set Management (DSM/TRIM) no
Host Protected Area (HPA)      yes      no      3907029168/3907029168
HPA - Security                 no

 

[FreeNASBob]

Further experimentation: I thought perhaps .system might be responsible, so I detached the pool and it had no effect on the load_cycle_counts. Even with the drive just powered on and not even mounted it continues to park and unpark the heads every minute.

 

[FreeNASBob]

It's .system, but it took a reboot to discover. Once I rebooted with no zpool to write to the parking slowed to twice in an hour. Looks like if I want to keep my hard drives longer than a year I'm going to have to get an SSD or SATADOM for .system to live on.

I knew .system would mess up my plans for low power consumption, but it hadn't occurred to me that it might trash my hard drives. Live and learn.