Ellis Giles

I was randomly getting hard drive error messages.  UNC means UNCorrectable ERRor, …. not good.  These messages were like:

Feb 17 10:40:34 server04 kernel: ata1.00: cmd 60/f8:08:85:fe:dd/00:00:18:00:00/40 tag 1 ncq 126976 in
Feb 17 10:40:34 server04 kernel: res 40/00:10:7d:00:de/00:00:18:00:00/40 Emask 0×1 (device error)
Feb 17 10:40:34 server04 kernel: ata1.00: status: { DRDY }
Feb 17 10:40:34 server04 kernel: ata1.00: cmd 60/08:10:7d:00:de/00:00:18:00:00/40 tag 2 ncq 4096 in
Feb 17 10:40:34 server04 kernel: res 40/00:10:7d:00:de/00:00:18:00:00/40 Emask 0×1 (device error)
Feb 17 10:40:34 server04 kernel: ata1.00: status: { DRDY }
Feb 17 10:40:39 server04 kernel: ata1.00: cmd 60/08:18:7d:ff:dd/00:00:18:00:00/40 tag 3 ncq 4096 in
Feb 17 10:40:39 server04 kernel: res 40/00:10:7d:00:de/00:00:18:00:00/40 Emask 0×1 (device error)
Feb 17 10:40:39 server04 kernel: ata1.00: status: { DRDY }

and

ata1.00: exception Emask 0×0 SAct 0×0 SErr 0×0 action 0×0
ata1.00: BMDMA stat 0×25
ata1.00: cmd c8/00:08:8f:01:3c/00:00:00:00:00/e1 tag 0 dma 4096 in
         res 51/40:00:8f:01:3c/00:00:00:00:00/01 Emask 0×9 (media error)
ata1.00: status: { DRDY ERR }
ata1.00: error: { UNC }
ata1.00: configured for UDMA/133
ata1: EH complete
ata1.00: exception Emask 0×0 SAct 0×0 SErr 0×0 action 0×0
ata1.00: BMDMA stat 0×25
ata1.00: cmd c8/00:08:8f:01:3c/00:00:00:00:00/e1 tag 0 dma 4096 in
         res 51/40:00:8f:01:3c/00:00:00:00:00/01 Emask 0×9 (media error)
ata1.00: status: { DRDY ERR }
ata1.00: error: { UNC }
ata1.00: configured for UDMA/133
ata1: EH complete

and

[ 6308.750919] ata1.00: exception Emask 0×0 SAct 0×0 SErr 0×0 action 0×0
[ 6308.750930] ata1.00: BMDMA stat 0×65
[ 6308.750939] ata1.00: cmd c8/00:08:27:45:94/00:00:00:00:00/e0 tag 0
dma 4096 in
[ 6308.750942]          res 51/40:08:28:45:94/00:00:00:00:00/e0 Emask
0×9 (media error)
[ 6308.750948] ata1.00: status: { DRDY ERR }
[ 6308.750951] ata1.00: error: { UNC }
[ 6308.757809] ata1: nv_mode_filter: 0×3f01f&0×3f01f->0×3f01f,
BIOS=0×3f000 (0xc600c0c0) ACPI=0×3f01f (20:600:0×13)
[ 6308.773842] ata1.00: configured for UDMA/100
[ 6308.774057] ata1: EH complete
[ 6315.576605] ata1.00: exception Emask 0×0 SAct 0×0 SErr 0×0 action 0×0
[ 6315.576616] ata1.00: BMDMA stat 0×65
[ 6315.576627] ata1.00: cmd c8/00:08:27:45:94/00:00:00:00:00/e0 tag 0
dma 4096 in
[ 6315.576629]          res 51/40:08:28:45:94/00:00:00:00:00/e0 Emask
0×9 (media error)
[ 6315.576635] ata1.00: status: { DRDY ERR }
[ 6315.576638] ata1.00: error: { UNC }
[ 6315.588519] ata1: nv_mode_filter: 0×3f01f&0×3f01f->0×3f01f,
BIOS=0×3f000 (0xc600c0c0) ACPI=0×3f01f (20:600:0×13)
[ 6315.608523] ata1.00: configured for UDMA/100
[ 6315.608711] ata1: EH complete

I obtained and ran the SmartCTL utility:

apt-get install smartmontools

smartctl -a /dev/sda

(or your hard drive)

You’ll see output like:

=== START OF READ SMART DATA SECTION ===
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0×000b   200   200   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0×0007   144   139   021    Pre-fail  Always       -       3325
  4 Start_Stop_Count        0×0032   094   094   040    Old_age   Always       -       6229
  5 Reallocated_Sector_Ct   0×0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0×000b   100   253   051    Pre-fail  Always       -       0
  9 Power_On_Hours          0×0032   084   084   000    Old_age   Always       -       11802
10 Spin_Retry_Count        0×0013   100   100   051    Pre-fail  Always       -       0
11 Calibration_Retry_Count 0×0013   100   100   051    Pre-fail  Always       -       0
12 Power_Cycle_Count       0×0032   094   094   000    Old_age   Always       -       6203
194 Temperature_Celsius     0×0022   111   253   000    Old_age   Always       -       39
196 Reallocated_Event_Count 0×0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0×0012   200   200   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0×0012   200   200   000    Old_age   Always       -       0
199 UDMA_CRC_Error_Count    0×000a   200   253   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0×0009   200   155   051    Pre-fail  Offline      -       0

A retry, error, or pending count can mean bad sectors!

Luckily if you’re running ext4, or another journaling file system, these errors may recover and you can backup you machine, install a RAID and get on with life!

You might run into posts that say that adding kernel options like:

“options libata noacpi=1″ on /etc/modprobe.d/options

may not show errors of these types again, but hiding errors is not a good idea.  The above errors are symptoms of a failing drive and should be replace immediately.

Even if fsck runs fine, you should force an fsck check.  See my other post on running fsck.

Filed under: Technology | Tagged: Hard Drive, Sector Error, Ubuntu