# [solved] HD access via NFS => kernel errors

## Jimini

Hi,

my fileserver shares some of its folders via NFS. Since a few days I have the problem, that its kernel log is full of errors. I could reproduce them by accessing one of these folders from my desktop pc.

These lines are added when I am accessing one single videofile:

```
[2010-08-02 02:01:36] err kern kernel [1534071.001826] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:36] err kern kernel [1534071.001834] ata4.00: BMDMA stat 0x26                  

[2010-08-02 02:01:36] err kern kernel [1534071.001842] ata4.00: failed command: READ DMA EXT           

[2010-08-02 02:01:36] err kern kernel [1534071.001857] ata4.00: cmd 25/00:a8:ba:51:d1/00:00:6c:00:00/e0 tag 0 dma 86016 in

[2010-08-02 02:01:36] err kern kernel [1534071.001862]          res 51/84:67:ba:51:d1/84:00:6c:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:36] err kern kernel [1534071.001871] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:36] err kern kernel [1534071.001877] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:36] info kern kernel [1534071.001899] ata4: soft resetting link          

[2010-08-02 02:01:36] info kern kernel [1534071.158202] ata4.00: configured for UDMA/33

[2010-08-02 02:01:36] info kern kernel [1534071.158224] ata4: EH complete                     

[2010-08-02 02:01:36] err kern kernel [1534071.229068] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:36] err kern kernel [1534071.229080] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:36] err kern kernel [1534071.229090] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:36] err kern kernel [1534071.229110] ata4.00: cmd 25/00:a8:4a:6e:9d/00:00:6c:00:00/e0 tag 0 dma 86016 in

[2010-08-02 02:01:36] err kern kernel [1534071.229115]          res 51/84:77:4a:6e:9d/84:00:6c:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:36] err kern kernel [1534071.229125] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:36] err kern kernel [1534071.229132] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:36] info kern kernel [1534071.229156] ata4: soft resetting link

[2010-08-02 02:01:36] info kern kernel [1534071.389202] ata4.00: configured for UDMA/33

[2010-08-02 02:01:36] info kern kernel [1534071.389224] ata4: EH complete

[2010-08-02 02:01:36] err kern kernel [1534071.451182] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:36] err kern kernel [1534071.451190] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:36] err kern kernel [1534071.451197] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:36] err kern kernel [1534071.451212] ata4.00: cmd 25/00:a0:e2:82:9d/00:00:6c:00:00/e0 tag 0 dma 81920 in

[2010-08-02 02:01:36] err kern kernel [1534071.451215]          res 51/84:0f:e2:82:9d/84:00:6c:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:36] err kern kernel [1534071.451222] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:36] err kern kernel [1534071.451227] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:36] info kern kernel [1534071.451243] ata4: soft resetting link

[2010-08-02 02:01:36] info kern kernel [1534071.611201] ata4.00: configured for UDMA/33

[2010-08-02 02:01:36] info kern kernel [1534071.611229] ata4: EH complete

[2010-08-02 02:01:37] err kern kernel [1534072.862476] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:37] err kern kernel [1534072.862484] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:37] err kern kernel [1534072.862492] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:37] err kern kernel [1534072.862506] ata4.00: cmd 25/00:20:22:d5:f5/00:00:5d:00:00/e0 tag 0 dma 16384 in

[2010-08-02 02:01:37] err kern kernel [1534072.862510]          res 51/84:0f:22:d5:f5/84:00:5d:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:37] err kern kernel [1534072.862517] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:37] err kern kernel [1534072.862522] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:37] info kern kernel [1534072.862538] ata4: soft resetting link

[2010-08-02 02:01:38] info kern kernel [1534073.022209] ata4.00: configured for UDMA/33

[2010-08-02 02:01:38] info kern kernel [1534073.022237] ata4: EH complete

[2010-08-02 02:01:38] err kern kernel [1534073.128650] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:38] err kern kernel [1534073.128658] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:38] err kern kernel [1534073.128667] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:38] err kern kernel [1534073.128682] ata4.00: cmd 25/00:80:ba:17:f6/00:00:5d:00:00/e0 tag 0 dma 65536 in

[2010-08-02 02:01:38] err kern kernel [1534073.128685]          res 51/84:00:ba:17:f6/84:00:5d:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:38] err kern kernel [1534073.128692] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:38] err kern kernel [1534073.128697] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:38] info kern kernel [1534073.128714] ata4: soft resetting link

[2010-08-02 02:01:38] info kern kernel [1534073.288201] ata4.00: configured for UDMA/33

[2010-08-02 02:01:38] info kern kernel [1534073.288223] ata4: EH complete

[2010-08-02 02:01:38] err kern kernel [1534073.374829] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:38] err kern kernel [1534073.374838] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:38] err kern kernel [1534073.374845] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:38] err kern kernel [1534073.374860] ata4.00: cmd 25/00:e8:62:6e:86/00:00:5f:00:00/e0 tag 0 dma 118784 in

[2010-08-02 02:01:38] err kern kernel [1534073.374863]          res 51/84:d7:62:6e:86/84:00:5f:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:38] err kern kernel [1534073.374870] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:38] err kern kernel [1534073.374875] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:38] info kern kernel [1534073.374891] ata4: soft resetting link

[2010-08-02 02:01:38] info kern kernel [1534073.531203] ata4.00: configured for UDMA/33

[2010-08-02 02:01:38] info kern kernel [1534073.531224] ata4: EH complete

[2010-08-02 02:01:38] err kern kernel [1534073.888292] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:38] err kern kernel [1534073.888299] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:38] err kern kernel [1534073.888307] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:38] err kern kernel [1534073.888322] ata4.00: cmd 25/00:c0:ba:97:8f/00:00:60:00:00/e0 tag 0 dma 98304 in

[2010-08-02 02:01:38] err kern kernel [1534073.888325]          res 51/84:2f:ba:97:8f/84:00:60:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:38] err kern kernel [1534073.888332] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:38] err kern kernel [1534073.888337] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:38] info kern kernel [1534073.888353] ata4: soft resetting link

[2010-08-02 02:01:39] info kern kernel [1534074.048201] ata4.00: configured for UDMA/33

[2010-08-02 02:01:39] info kern kernel [1534074.048223] ata4: EH complete

[2010-08-02 02:01:39] err kern kernel [1534074.062440] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:39] err kern kernel [1534074.062447] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:39] err kern kernel [1534074.062455] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:39] err kern kernel [1534074.062469] ata4.00: cmd 25/00:d8:d2:70:86/00:00:5f:00:00/e0 tag 0 dma 110592 in

[2010-08-02 02:01:39] err kern kernel [1534074.062473]          res 51/84:c7:d2:70:86/84:00:5f:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:39] err kern kernel [1534074.062480] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:39] err kern kernel [1534074.062485] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:39] info kern kernel [1534074.062501] ata4: soft resetting link

[2010-08-02 02:01:39] info kern kernel [1534074.222201] ata4.00: configured for UDMA/33

[2010-08-02 02:01:39] info kern kernel [1534074.222229] ata4: EH complete

[2010-08-02 02:01:42] err kern kernel [1534077.235152] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:42] err kern kernel [1534077.235160] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:42] err kern kernel [1534077.235167] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:42] err kern kernel [1534077.235182] ata4.00: cmd 25/00:70:a2:b3:9f/00:00:6c:00:00/e0 tag 0 dma 57344 in

[2010-08-02 02:01:42] err kern kernel [1534077.235185]          res 51/84:2f:a2:b3:9f/84:00:6c:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:42] err kern kernel [1534077.235192] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:42] err kern kernel [1534077.235197] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:42] info kern kernel [1534077.235213] ata4: soft resetting link

[2010-08-02 02:01:42] info kern kernel [1534077.395201] ata4.00: configured for UDMA/33

[2010-08-02 02:01:42] info kern kernel [1534077.395219] ata4: EH complete

[2010-08-02 02:01:43] err kern kernel [1534078.677382] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6

[2010-08-02 02:01:43] err kern kernel [1534078.677392] ata4.00: BMDMA stat 0x26

[2010-08-02 02:01:43] err kern kernel [1534078.677403] ata4.00: failed command: READ DMA EXT

[2010-08-02 02:01:43] err kern kernel [1534078.677424] ata4.00: cmd 25/00:f8:72:77:9d/00:00:6c:00:00/e0 tag 0 dma 126976 in

[2010-08-02 02:01:43] err kern kernel [1534078.677429]          res 51/84:47:72:77:9d/84:00:6c:00:00/e0 Emask 0x30 (host bus error)

[2010-08-02 02:01:43] err kern kernel [1534078.677439] ata4.00: status: { DRDY ERR }

[2010-08-02 02:01:43] err kern kernel [1534078.677447] ata4.00: error: { ICRC ABRT }

[2010-08-02 02:01:43] info kern kernel [1534078.677472] ata4: soft resetting link

[2010-08-02 02:01:43] info kern kernel [1534078.837204] ata4.00: configured for UDMA/33

[2010-08-02 02:01:43] info kern kernel [1534078.837227] ata4: EH complete
```

SMART-check:

```
Atlas log # smartctl -H /dev/sdb

smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen

Home page is http://smartmontools.sourceforge.net/

=== START OF READ SMART DATA SECTION ===

SMART overall-health self-assessment test result: PASSED

Atlas log # smartctl -H /dev/sdc

smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen

Home page is http://smartmontools.sourceforge.net/

=== START OF READ SMART DATA SECTION ===

SMART overall-health self-assessment test result: PASSED
```

This problem occurs since july 25th, on this day I have not emerged anything or made any changes at the system.

At the moment I use 2.6.34-gentoo-r1 on a Intel D945GCLF with 2 hard disks running in a RAID1.

Any ideas?

Best regards,

Jimini

----------

## BradN

the health self-assessment SMART provides is useless.  Even on horribly failing drives, it will still say it's healthy.

Instead use smartctl -a to retrieve all data, then look at the reallocated sector count and last error logs.

Because your problem occurs when accessing a specific file, then either an unreadable sector on your hard disk is likely causing it, or the filesystem is corrupted and it's trying to read a block that doesn't exist.

Check the hard drive with badblocks to verify errors, then recover damaged files from backup if needed.  hdparm has a command to issue single sector writes that may clear up bad sectors by making the drive reallocate them (but the data stored there is already lost).

If badblocks finds no errors, remount that partition read-only (use a boot cd if it's your root partition) and check the filesystem with the fsck tool for that FS.

----------

## Jimini

There is a little misunderstanding - these errors occure all the time, the file I mentioned above was just an example. My log file grew by 24 M within two days, because these errors are logged almost secondly. 

smartctl -a /dev/sdb

```
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     0x002f   200   200   051    Pre-fail  Always       -       0

  3 Spin_Up_Time            0x0027   187   172   021    Pre-fail  Always       -       5608

  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       130

  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0

  7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0

  9 Power_On_Hours          0x0032   094   094   000    Old_age   Always       -       4574

 10 Spin_Retry_Count        0x0032   100   100   000    Old_age   Always       -       0

 11 Calibration_Retry_Count 0x0032   100   100   000    Old_age   Always       -       0

 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       128

192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       44

193 Load_Cycle_Count        0x0032   098   098   000    Old_age   Always       -       307660

194 Temperature_Celsius     0x0022   109   104   000    Old_age   Always       -       41

196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0

197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0

198 Offline_Uncorrectable   0x0030   200   200   000    Old_age   Offline      -       0

199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0

200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       0
```

smartctl -a /dev/sdc

```
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     0x002f   200   200   051    Pre-fail  Always       -       0

  3 Spin_Up_Time            0x0027   190   177   021    Pre-fail  Always       -       5491

  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       131

  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0

  7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0

  9 Power_On_Hours          0x0032   094   094   000    Old_age   Always       -       4575

 10 Spin_Retry_Count        0x0032   100   100   000    Old_age   Always       -       0

 11 Calibration_Retry_Count 0x0032   100   100   000    Old_age   Always       -       0

 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       129

192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       44

193 Load_Cycle_Count        0x0032   098   098   000    Old_age   Always       -       307450

194 Temperature_Celsius     0x0022   108   103   000    Old_age   Always       -       42

196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0

197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0

198 Offline_Uncorrectable   0x0030   200   200   000    Old_age   Offline      -       0

199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       109791

200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       0
```

The value "UDMA_CRC_Error_Count" on my second disk is very high, so I'm going to check the cables today. This value also explains the "DMA 33" entries in my log file.

Best regards,

Jimini

----------

## Jimini

I changed both SATA cables and rebooted the machine one hour ago. Since the reboot, no new error messages appeared in my syslog, so I assume, that a defect cable caused this mess. 

Thanks for your hint with smartctl -a!

Best regards,

Jimini

----------

