如何在实践中使用智能How？

Question

我只是随便用smartctl来窥视我的磁盘，而不是真正地潜入其中。在阅读了黑客新闻述评之后，我决定安排每日、短时和每周的长时间测试。

如何更好地利用它们？

当我查看smartctl -a /dev/sda的结果时，我看到了许多不太明显的信息：

# smartctl -a /dev/sda
smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.15.0-32-generic] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Crucial/Micron MX100/MX200/M5x0/M600 Client SSDs
Device Model:     Crucial_CT500MX200SSD4
Serial Number:    160311862C1C
LU WWN Device Id: 5 00a075 111862c1c
Firmware Version: MU03
User Capacity:    500,107,862,016 bytes [500 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    Solid State Device
Form Factor:      < 1.8 inches
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-3 T13/2161-D revision 4
SATA Version is:  SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Mon Sep  3 10:49:49 2018 CEST
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:  (0x80) Offline data collection activity
                                        was never started.
                                        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:                ( 1271) 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:        (   7) minutes.
Conveyance self-test routine
recommended polling time:        (   3) minutes.
SCT capabilities:              (0x0035) SCT Status 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   100   100   000    Pre-fail  Always       -       0
  5 Reallocate_NAND_Blk_Cnt 0x0032   100   100   010    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       16446
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       44
171 Program_Fail_Count      0x0032   100   100   000    Old_age   Always       -       0
172 Erase_Fail_Count        0x0032   100   100   000    Old_age   Always       -       0
173 Ave_Block-Erase_Count   0x0032   094   094   000    Old_age   Always       -       139
174 Unexpect_Power_Loss_Ct  0x0032   100   100   000    Old_age   Always       -       29
180 Unused_Reserve_NAND_Blk 0x0033   000   000   000    Pre-fail  Always       -       5548
183 SATA_Interfac_Downshift 0x0032   100   100   000    Old_age   Always       -       0
184 Error_Correction_Count  0x0032   100   100   000    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0022   058   049   000    Old_age   Always       -       42 (Min/Max 23/51)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   100   100   000    Old_age   Always       -       0
202 Percent_Lifetime_Used   0x0030   094   094   001    Old_age   Offline      -       6
206 Write_Error_Rate        0x000e   100   100   000    Old_age   Always       -       0
210 Success_RAIN_Recov_Cnt  0x0032   100   100   000    Old_age   Always       -       0
246 Total_Host_Sector_Write 0x0032   100   100   000    Old_age   Always       -       15420692355
247 Host_Program_Page_Count 0x0032   100   100   000    Old_age   Always       -       481912759
248 Bckgnd_Program_Page_Cnt 0x0032   100   100   000    Old_age   Always       -       1753257160

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%     16446         -
# 2  Short offline       Completed without error       00%     10532         -
# 3  Short offline       Completed without error       00%      8040         -
# 4  Vendor (0xff)       Completed without error       00%      3608         -
# 5  Vendor (0xff)       Completed without error       00%       597         -
# 6  Vendor (0xff)       Completed without error       00%       585         -
# 7  Vendor (0xff)       Completed without error       00%       520         -
# 8  Vendor (0xff)       Completed without error       00%       161         -
# 9  Vendor (0xff)       Completed without error       00%        98         -
#10  Vendor (0xff)       Completed without error       00%        65         -

SMART Selective self-test log data structure revision number 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Completed [00% left] (57881389-57946924)
    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.

具体来说，没有明确的迹象表明

• 错误
• 测试史

除了不时运行smartctl -a /dev/sdX并希望发现任何不寻常的事件之外，是否有最佳的分析实践？

Answer 1

如果您已经配置了智能工具，以便它可以发送电子邮件，那么如果它发现了问题，就会收到电子邮件。

除此之外，在smartctl的S输出中可以看到错误和日志。我倾向于首先查看“Offline_Uncorrectable”字段，因为非零意味着驱动器无法处理的介质中存在缺陷(在您的例子中，使用SSD，通常意味着驱动器已经耗尽了对已经死亡的细胞的替换闪光灯)。其他属性表示读或写错误，但它们的重要性取决于错误的原因。

驱动器错误也记录在错误日志中：

SMART Error Log Version: 1
No Errors Logged

和测试日志中的测试结果：

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%     16446         -
# 2  Short offline       Completed without error       00%     10532         -
# 3  Short offline       Completed without error       00%      8040         -
# 4  Vendor (0xff)       Completed without error       00%      3608         -
# 5  Vendor (0xff)       Completed without error       00%       597         -
# 6  Vendor (0xff)       Completed without error       00%       585         -
# 7  Vendor (0xff)       Completed without error       00%       520         -
# 8  Vendor (0xff)       Completed without error       00%       161         -
# 9  Vendor (0xff)       Completed without error       00%        98         -
#10  Vendor (0xff)       Completed without error       00%        65         -

在这里，您需要标记为“已完成无错误”的测试，其中包含一个与驱动器当前生存期不太远的生存期字段(取决于测试计划)。在你的情况下，驱动器的寿命是16446小时，你有一个刚刚完成的测试。您还希望定期看到扩展的脱机测试，因为这是某些属性被更新的时候(例如，脱机不可纠正)。

我倾向于使用smartctl -x而不是smartctl -a，它显示了更多的信息。

Answer 2

这种智能技术大约在十几年前就开始于磁盘上，内部记录表面的潜在问题。您正在使用SSD磁盘，这是基于完全不同的技术(被称为电子可擦可编程ROM)。数据写在磁盘上称为扇区的块中，而在SSD上，数据是用更大的块写的，在写块之前(实际上是编程的)它必须被擦除。擦除块使块元素受到很小的损坏，因此固件试图将写入(=erasings=damages)均匀地传播到所有块上，因为对同一块的线材数量有限(SLC约为100000倍，MLC约为5000倍，TLC约为300倍)。

那么，smartctl报告的错误对于这两种基本的技术都有其他的意义。在磁盘上，您需要检查Current_Pending_Sector --指示不良写入(不可读)数据(ID 197)和指示不良磁面的Reallocated_sector_count (ID 5)，以及ID 194 Temperature_Celsius。在SSD中，ID 5被重命名为Reallocate_NAND_Blk_Cnt，它显示了生命时间之外的块数。

在这两种情况下，简单地存在几个坏块(扇区)并不一定意味着磁盘已经退出。问题可能是当许多有问题的区块突然出现时，或者它们的数量在日益增加。

延长磁盘的生存期，可以谨慎地选择合适的品牌和类型(服务器24x7、桌面、录像机)，并尽可能地以良好的条件支持它(风扇用于降低温度、足够的功率、严格的水平或垂直位置)。

SSD磁盘的生存期可以通过选择SLC来扩展(慢速但更好)--今天您只可以购买MLC，但即使是那些可以比TLC更长的寿命。并对不必要的写作做任何可能的限制。因此，您必须将交换(pagefile.sys)作为用户目录(homes)和日志文件移到磁盘上。在linux中，您可以额外添加noatime、nodiratime挂载选项。经常做备份！定期检查智能系统可能很有帮助，但不能将丢失的数据还给您。