Linux
有故障的魚子醬藍硬碟？
我們有一個小型“自製”伺服器，執行完全更新的 Debian Wheezy (amd64)。安裝了一個硬碟驅動器：WDC WD6400AAKS。主機板是華碩M4N68T V2。
正常負載：
- CPU：平均20%
- 每周大約會佔用 50GB 的額外空間。大約 47GB 的上傳文件和 3GB 的 MySQL 數據。
恐怕硬碟驅動器即將發生故障。我跑的時候在幾個地方看到了Pre-fail ：
root@SERVER:/tmp# smartctl -a /dev/sda smartctl 5.41 2011-06-09 r3365 [x86_64-linux-3.2.0-4-amd64] (local build) Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Model Family: Western Digital Caviar Blue Serial ATA Device Model: WDC WD6400AAKS-XXXXXXX Serial Number: WD-XXXXXXXXXXXXXXXXXXX LU WWN Device Id: 5 0014ee XXXXXXXXXXXXX Firmware Version: 01.03B01 User Capacity: 640,135,028,736 bytes [640 GB] Sector Size: 512 bytes logical/physical Device is: In smartctl database [for details use: -P show] ATA Version is: 8 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Mon Oct 28 18:55:27 2013 UTC SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED General SMART Values: Offline data collection status: (0x85) Offline data collection activity was aborted by an interrupting command from host. Auto Offline Data Collection: Enabled. Self-test execution status: ( 247) Self-test routine in progress... 70% of test remaining. Total time to complete Offline data collection: (11580) 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: ( 2) minutes. Extended self-test routine recommended polling time: ( 136) minutes. Conveyance self-test routine recommended polling time: ( 5) minutes. SCT capabilities: (0x303f) SCT Status supported. SCT Error Recovery Control supported. SCT Feature Control supported. SCT Data Table supported. 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 157 146 021 Pre-fail Always - 5108 4 Start_Stop_Count 0x0032 098 098 000 Old_age Always - 2968 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 200 200 051 Old_age Always - 0 9 Power_On_Hours 0x0032 079 079 000 Old_age Always - 15445 10 Spin_Retry_Count 0x0032 100 100 051 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 100 100 051 Old_age Always - 0 12 Power_Cycle_Count 0x0032 098 098 000 Old_age Always - 2950 192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 426 193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always - 2968 194 Temperature_Celsius 0x0022 111 095 000 Old_age Always - 36 196 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 200 160 000 Old_age Always - 21716 200 Multi_Zone_Error_Rate 0x0008 200 200 051 Old_age Offline - 0 SMART Error Log Version: 1 No Errors Logged SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Short offline Completed without error 00% 15444 - Error SMART Read Selective Self-Test Log failed: scsi error aborted command Smartctl: SMART Selective Self Test Log Read Failed root@SERVER:/tmp#在一個教程中，我讀到預失敗表示即將失敗，在另一個教程中，我讀到這不是真的。你們能幫我解碼smartctl的輸出嗎？
如果我想確保數據完整性（每周大約 50GB 的新數據，我感興趣的整個期間最多 2TB），我也很高興分享我應該怎麼做的建議。也許我會在 RAID4 中使用 2x2TB Caviar Black？
如前所述，“Prefail”文本僅指示條目的類型。並且根據條目，並非每個條目都是錯誤的。例如 Spin_Up_Time 只計算驅動器啟動的頻率，Load_Cycle_Count 計算磁頭停放的頻率。
讓我暫停的值是 21716 處的 UDMA_CRC_Error_Count。這可能是由於電纜損壞/鬆動或電子故障引起的。
如果存在表面錯誤，則 Reallocated_Sector_Ct、Current_Pending_Sector 或 Offline_Uncorrectable 會上升。它們都是 0，所以磁碟可能完全沒問題。
以下表示有一個測試仍在執行：
Self-test execution status: ( 247) Self-test routine in progress... 70% of test remaining.完成後，“SMART Self-test log structure”部分中應該有另一個條目。您應該使用長測試 (smartctl -t long) 來獲得有意義的結果。記錄的測試只是一個簡短的測試。
關於更高的數據完整性：RAID4 至少需要 3 個磁碟並且不再使用（由 RAID5 代替）。但在您的情況下，具有 2 個磁碟的 RAID1 或具有 4 個磁碟的 RAID10 都適合。兩種模式都將可用空間量減半，但如果一個驅動器發生故障，仍可繼續工作。RAID10 具有速度更快的優勢，因為它將負載分配到更多驅動器上，並且取決於哪些驅動器發生故障，即使 2 個發生故障的驅動器也能倖免於難。如果一個磁碟足夠快，RAID1 也足夠快（寫入速度相同，數據量大時讀取速度加倍）。