Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have Ubuntu 12.10, on an SSD (OCZ Agility 3 128GB), with a modestly overclocked i5-2500k (4.4GHz) on motherboard P8Z68V_LX. I think there may be a problem with the SSD. Its fairly unused, and is currently only 11% full.

Running ruby on rails, when things sometimes mysteriously break, its usually because somewhere in the core libraries a letter appears to have changed. For example, in a hash an "S" had been changed to a "{", and days later in a spork file the title of a def had changed to "s{ite" when it should clearly have been "suite".

Ubuntu has been experiencing many internal errors and has been unable to report them, thus spawning another error to report that... and so on. Sometimes it complains of incorrect padding.

This isn't my main work machine so I'm eager to experiment on it to find out what it is.

smartctl spewed out:

> sudo smartctl -a /dev/sda
smartctl 5.43 2012-06-30 r3573 [x86_64-linux-3.5.0-27-generic] (local build)
Copyright (C) 2002-12 by Bruce Allen,

Model Family:     SandForce Driven SSDs
Device Model:     OCZ-AGILITY3
Serial Number:    OCZ-822QB5MV0QDI394P
LU WWN Device Id: 5 e83a97 e3d1ecf1a
Firmware Version: 2.15
User Capacity:    120,034,123,776 bytes [120 GB]
Sector Size:      512 bytes logical/physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   8
ATA Standard is:  ACS-2 revision 3
Local Time is:    Thu Apr 18 15:40:12 2013 BST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status:  (0x02) Offline data collection activity
          was completed without error.
          Auto Offline Data Collection: Disabled.
Self-test execution status:      (   1) The previous self-test routine completed
          without error or no self-test has ever
          been run.
Total time to complete Offline
data collection:    ( 1465) seconds.
Offline data collection
capabilities:        (0x7f) SMART execute Offline immediate.
          Auto Offline data collection on/off support.
          Abort Offline collection upon new
          Offline surface scan supported.
          Self-test supported.
          Conveyance Self-test supported.
          Selective Self-test supported.
SMART capabilities:            (0x0003) Saves SMART data before entering
          power-saving mode.
          Supports SMART auto save timer.
Error logging capability:        (0x01) Error logging supported.
          General Purpose Logging supported.
Short self-test routine
recommended polling time:    (   1) minutes.
Extended self-test routine
recommended polling time:    (  48) minutes.
Conveyance self-test routine
recommended polling time:    (   2) minutes.
SCT capabilities:          (0x0021) SCT Status supported.
          SCT Data Table supported.

SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
  1 Raw_Read_Error_Rate     0x000f   090   090   050    Pre-fail  Always       -       0/2566041
  5 Retired_Block_Count     0x0033   100   100   003    Pre-fail  Always       -       0
  9 Power_On_Hours_and_Msec 0x0032   100   100   000    Old_age   Always       -       731h+39m+09.960s
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       256
171 Program_Fail_Count      0x0032   000   000   000    Old_age   Always       -       0
172 Erase_Fail_Count        0x0032   000   000   000    Old_age   Always       -       0
174 Unexpect_Power_Loss_Ct  0x0030   000   000   000    Old_age   Offline      -       68
177 Wear_Range_Delta        0x0000   000   000   000    Old_age   Offline      -       1
181 Program_Fail_Count      0x0032   000   000   000    Old_age   Always       -       0
182 Erase_Fail_Count        0x0032   000   000   000    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0022   030   030   000    Old_age   Always       -       30 (Min/Max 30/30)
195 ECC_Uncorr_Error_Count  0x001c   120   120   000    Old_age   Offline      -       0/2566041
196 Reallocated_Event_Count 0x0033   100   100   003    Pre-fail  Always       -       0
201 Unc_Soft_Read_Err_Rate  0x001c   120   120   000    Old_age   Offline      -       0/2566041
204 Soft_ECC_Correct_Rate   0x001c   120   120   000    Old_age   Offline      -       0/2566041
230 Life_Curve_Status       0x0013   100   100   000    Pre-fail  Always       -       100
231 SSD_Life_Left           0x0013   100   100   010    Pre-fail  Always       -       0
233 SandForce_Internal      0x0000   000   000   000    Old_age   Offline      -       481
234 SandForce_Internal      0x0032   000   000   000    Old_age   Always       -       454
241 Lifetime_Writes_GiB     0x0032   000   000   000    Old_age   Always       -       454
242 Lifetime_Reads_GiB      0x0032   000   000   000    Old_age   Always       -       1025

SMART Error Log not supported
SMART Self-test Log not supported
SMART Selective self-test log data structure revision number 1
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x0):
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.


Have run Memtest86, initially it was displaying many errors from second pass, so i restarted and checked the BIOS voltages, they were all ok. Downclocked to normal speed of 3.3GHz, rechecked voltages, all ok.


CPU  : 1.096V
3.3V : 3.344V
5V   : 5.000V
12V  : 12.096V

Reran Memtest86 overnight:

Time 16:23:23  Iterations: 6  AdsrMode:64Bit   Pass: 24 Errors:65535+

Error Confidence Value: 50
Lowest Error Address: 00180a73000 - 6154.4MB
Highest Error Address: 001dffffffc - 7679.9MB
Bits in Error Mask: ffffffff
Bits in Error - Total: 32  Min: 1  Max:31  Avg:32768
Max Contiguous Errors: 65535+

Following the docs on MemTest86, it suggests that a confidence value above 100 suggests certainty of memory problems. Given that its only 50, i'll swap the RAM around and see if its the RAM or the motherboard.


I swapped the 2 4GB Ram Sticks around between A2 and B2 (that's how they're supposed to go in, not A1 and B1, that would be too intuitive) ran memtest, 6 passes and nothing happened. Overclocked to 4.3GHz, 6 passes and nothing again. Perhaps, I didn't seat the RAM properly...


Left it running over the weekend, found errors which suggest it may be a problem with the motherboard:

Time:  61:07:22   Iterations:240   AdrsMode:64Bit   Pass: 106   Errors: 65535+

Error Confidence Value: 77
Lowest Error Address  : 001c0027000 -  7168.1MB
Highest Error Address : 001dffffffc -  7679.9MB
Bits in Error Mask    : ffffffff
Bits in Error - Total : 32  Min: 1  Max: 31  Avg: 32768
Max Contiguous Errors : 65535+

My best guess is because the address is still high up (above 4GB after swapping the ram between the used slots) its a problem with the motherboard.


Put RAM into slots A1 and B1. MemTest has done 44 passes, no errors. Certainly a motherboard problem - one of the slots is bad. I wouldn't be keen to blame the asus motherboard, it was probably the shipping or my oafish hands.

share|improve this question
Download the latest firmware for the drive from OCZ's support site and possibly do a secure erase and re-install Ubuntu. Also return your CPU to stock voltage to rule that out as well. – Bert Apr 18 '13 at 14:50
Running Memtest86 v4.2.0 on the second pass its found 125260 errors so far, think I need to replace the ram – xxjjnn Apr 18 '13 at 15:24
Definitely going to reinstall Ubuntu! Who knows what else is corrupted! – xxjjnn Apr 23 '13 at 7:47
1. i5 has Turbo Boost, it overclocks automatically. 2. What kind of heavy computations do you do, for which 4 cores are not enough? – ignis Apr 23 '13 at 7:58
This i5 has a 1/2/3/4 overclock,, which is significantly less than 4.3GHz. I'm running rspec and cuke tests, here are some performance figures in next comment: – xxjjnn Apr 23 '13 at 11:42
up vote 0 down vote accepted

The problem was with the motherboard, specifically there were memory errors when using a particular RAM slot. MemTest86 is a valuable tool!

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.