Analyzing Disk Health
This article shows how to analyse disk health using SMART tool.
Just because some errors are discovered, it doesn't mean that the disk needs to be replaced. There are multiple items to verify before asserting a disk is failing or not.
Whether or not the disk is failing or not it is a good practice to do regular backup:
- Toolpack configuration database
- Streamserver prompts
- CDR
Contents |
Retrieve disk health information
Execute the following command for each disk in your system
TMG800/TMG3200:
smartctl -a /dev/sda
TMG7800:
smartctl -a /dev/sda smartctl -a /dev/sdb
Analysing smartctl output
Disk information section
The first section shows hard disk information.
Example:
smartctl version 5.38 [x86_64-redhat-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION === Device Model: ST500DM002-1BD142 Serial Number: W2ABM3WL Firmware Version: KC45 User Capacity: 500,107,862,016 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 4 Local Time is: Thu May 9 19:57:04 2013 BDT SMART support is: Available - device has SMART capability. SMART support is: Enabled
SMART Overall
This section shows the overall status of the disk.
Check the line: "SMART overall-health self-assessment test result"
If that line is different from "PASSED", you will need to change the disk.
Example:
=== START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED General SMART Values: Offline data collection status: (0x82) Offline data collection activity was completed without error. Auto Offline Data Collection: Enabled. Self-test execution status: ( 0) The previous self-test routine completed without error or no self-test has ever been run. Total time to complete Offline data collection: ( 592) seconds. Offline data collection capabilities: (0x7b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. 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: ( 82) minutes. Conveyance self-test routine recommended polling time: ( 2) minutes. SCT capabilities: (0x303f) SCT Status supported. SCT Feature Control supported. SCT Data Table supported.
SMART Disk Attributes Analysis
The "WHEN_FAILED" is the column to analyse. If an attribute is different than "-", you should analyse what that attribute means.
Each manufacturers/models has their own attributes. Here is the list of the most important items:
- Reallocated Sectors Count
- Spin Retry Count
- End-to-End error / IOEDC
- Command Timeout
- Reallocation Event Count
- Current Pending Sector Count
- Uncorrectable Sector Count
- Offline Uncorrectable
- Off-Line Scan Uncorrectable Sector Count
- Soft Read Error Rate
- TA Counter Detected
- Drive Life Protection Status
Example:
SMART Attributes Data Structure revision number: 10 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 108 099 006 Pre-fail Always - 20746840 3 Spin_Up_Time 0x0003 100 100 000 Pre-fail Always - 0 4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 13 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0 7 Seek_Error_Rate 0x000f 087 060 030 Pre-fail Always - 510305350 9 Power_On_Hours 0x0032 093 093 000 Old_age Always - 6671 10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 13 183 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 0 184 Unknown_Attribute 0x0032 100 100 099 Old_age Always - 0 187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0 188 Unknown_Attribute 0x0032 100 100 000 Old_age Always - 0 189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0 190 Airflow_Temperature_Cel 0x0022 071 052 045 Old_age Always - 29 (Lifetime Min/Max 21/38) 194 Temperature_Celsius 0x0022 029 048 000 Old_age Always - 29 (0 21 0 0) 195 Hardware_ECC_Recovered 0x001a 048 045 000 Old_age Always - 20746840 197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 240 Head_Flying_Hours 0x0000 100 253 000 Old_age Offline - 108009837566479 241 Unknown_Attribute 0x0000 100 253 000 Old_age Offline - 2959021143 242 Unknown_Attribute 0x0000 100 253 000 Old_age Offline - 2656448388
SMART Error Log
The SMART Error Log will show the number of errors.
Having a few errors doesn't mean the disk need to be replace. A large number of errors (over a 1000) should be consider problematic.
Example:
SMART Error Log Version: 1 ATA Error Count: 18 (device log contains only the most recent five errors) CR = Command Register [HEX] FR = Features Register [HEX] SC = Sector Count Register [HEX] SN = Sector Number Register [HEX] CL = Cylinder Low Register [HEX] CH = Cylinder High Register [HEX] DH = Device/Head Register [HEX] DC = Device Command Register [HEX] ER = Error register [HEX] ST = Status register [HEX] Powered_Up_Time is measured from power on, and printed as DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes, SS=sec, and sss=millisec. It "wraps" after 49.710 days. Error 18 occurred at disk power-on lifetime: 4557 hours (189 days + 21 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 51 00 ff ff ff 0f Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- 60 00 80 ff ff ff 4f 00 17d+22:09:56.826 READ FPDMA QUEUED 60 00 80 ff ff ff 4f 00 17d+22:09:56.825 READ FPDMA QUEUED 60 00 80 ff ff ff 4f 00 17d+22:09:56.825 READ FPDMA QUEUED 60 00 80 ff ff ff 4f 00 17d+22:09:56.825 READ FPDMA QUEUED 60 00 80 ff ff ff 4f 00 17d+22:09:56.824 READ FPDMA QUEUED
SMART self-test
List of SMART test run on the system. The LBA_of_first_error element is the one to check. If it is different from "-", you may want to replace the disk
Example:
SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Extended offline Completed without error 00% 9747 - # 2 Short offline Completed without error 00% 1 -
Running SMART disk test
After analyzing the output of the "smartctl", there were some errors.
Please run the following (WARNING: Can be very long up to 27hours, but is not system affective)
smartctl -l selftest /dev/sda
