提要：大家心理最怕的不是安装某个系统，而是辛辛苦苦安装之后，忽然有一天硬盘坏了，又没有备份(DAT，DLT之类磁带机贵得吓死人)。怎么样才能知道你的硬盘能否过新年呢？(硬盘状态如何？) 特别是如果能够提前预报，告诉大家硬盘快顶不住了，那该有多好。
本文测试环境FreeBSD和Debian
解决办法：
SMART
SMART(SFF-8035i) 是硬盘生产商们建立的一个工业标准，这个标准就是在硬盘上保存一个跟执行情况，可靠程度，读找错误率等属性的表格。所有属性都有一个1byte(大小范围1-253)的标准化值，还包含另一个1byte的关键阶段值，如果属性表格内某个数据接近小于或达到关键阶段值，那么你的硬盘就快跟你永别了，至少也是超过它的设计使用极限了- 该做备份和最坏的打算了。
SFF-8035i工业标准经过ATA-3，ATA-4到了ATA-5，加入了一个错误信息文件(error log) 和一系列硬盘自测SMART命令。SMART适应与IDE和SCSI硬盘。
我用FreeBSD 5.2和Debian做了实验，都不错，OpenBSD下面可以直接用atactl，大家看看man atactl。其它linux系统没问题。
安装 smartmontools
FreeBSD:
#/usr/ports/sysutils/smartmontools
#make install clean
#cp /usr/local/etc/rc.d/smartd.sh.sample /usr/local/etc/rc.d/smartd.sh
#cp /usr/local/etc/smartd.conf.sample /usr/local/etc/smartd.conf
#chmod 555 /usr/local/etc/rc.d/smartd.sh
Debian:
apt-get install smartmontool*
/etc/smartd.conf
FreeBSD设置文件/usr/local/etc/smartd.conf
Debian设置文件 /etc/smartd.conf
注意：
千万不要忘了改写设置文件！！！！
FreeBSD下第一张IDE硬盘是ad0，SCSI硬盘是da0
Debian下第一张IDE硬盘是/dev/hda，SCSI硬盘是/dev/sda
下面我用FreeBSD做例子，我的硬盘是IDE，如果你的是SCSI，你就去官方网站查询。
启动监护程序：
/usr/local/etc/rc.d/smartd.sh start
首先让我们看一下你的硬盘是否支持SMART：
bash-2.05b# smartctl -i /dev/ad0
smartctl version 5.26 Copyright (C) 2002-3 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
=== START OF INFORMATION SECTION ===
Device Model: IBM-DJSA-220
Serial Number: 44K443Z0103
Firmware Version: JS4OAC3A
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: 5
ATA Standard is: ATA/ATAPI-5 T13 1321D revision 1
Local Time is: Mon Dec 22 21:04:38 2003 CET
SMART support is: Available - device has SMART capability.
SMART support is: enable
The SMART RETURN STATUS return value (smartmontools -H option/Directive)
can not be retrieved with this version of ATAng, please do not rely on this value
看看我的盘健康测试，如果你的self-assessment test result是FAILING，那就是说
它要完蛋了，马上备份！！！
bash-2.05b# smartctl -Hc /dev/ad0
smartctl version 5.26 Copyright (C) 2002-3 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
The SMART RETURN STATUS return value (smartmontools -H option/Directive)
can not be retrieved with this version of ATAng, please do not rely on
this value
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x00) Offline data collection activity
was
never started.
Auto Offline Data Collection: Disabled.
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: ( 650) seconds.
Offline data collection
capabilities: (0x1b) SMART execute Offline immediate.
Auto Offline data collection on/off
support.
Suspend Offline collection upon
new
command.
Offline surface scan supported.
Self-test supported.
No Conveyance Self-test supported.
No 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.
No General Purpose Logging support.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: ( 29) minutes.
下面表格给出的属性信息根据你的硬盘厂商不同而不同，最 重要的是明白每个纵行的意义：如果有一个标准值(VALUE)小于或等於关键值(THRESH)时，WHEN_FAILED 行会给出信息，我WHEN_FAILED纵行是空行，说明没事儿。如果WHEN_FAILED报错，硬盘有问题了。。。。WORST 是标准值(VALUE)的最小值。
bash-2.05b# smartctl -A /dev/ad0
smartctl version 5.26 Copyright (C) 2002-3 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
The SMART RETURN STATUS return value (smartmontools -H option/Directive)
can not be retrieved with this version of ATAng, please do not rely on
this value
=== START OF READ SMART DATA SECTION ===
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 0x000b 100 100 062 Pre-fail Always
- 0
2 Throughput_Performance 0x0005 100 100 040 Pre-fail Offline
- 0
3 Spin_Up_Time 0x0007 113 113 033 Pre-fail Always
- 1
4 Start_Stop_Count 0x0012 100 100 000 Old_age Always
- 985
5 Reallocated_Sector_Ct 0x0033 100 100 005 Pre-fail Always
- 0
7 Seek_Error_Rate 0x000b 100 100 067 Pre-fail Always
- 0
8 Seek_Time_Performance 0x0005 100 100 040 Pre-fail Offline
- 0
9 Power_On_Hours 0x0012 097 097 000 Old_age Always
- 1642
10 Spin_Retry_Count 0x0013 100 100 060 Pre-fail Always
- 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always
- 914
191 G-Sense_Error_Rate 0x000a 100 100 000 Old_age Always
- 0
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always
- 8
193 Load_Cycle_Count 0x0012 096 096 050 Old_age Always
- 45262
196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always
- 17
197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always
- 1
198 Offline_Uncorrectable 0x0008 100 100 000 Old_age Offline
- 0
199 UDMA_CRC_Error_Count 0x000a 200 200 000 Old_age Always
- 0
下面命令给出硬盘历史错误信息(error log),因为篇幅关系我就不给出了。
smartctl -l error /dev/ad0
下面命令给出硬盘自测
smartctl -l selftest /dev/ad0
终止硬盘自测。
smartctl -X /dev/ad0
建议：改写设置文件smartd.conf，有一个“-m”的选项非常有用，它可以把信息用mail发给你。
编辑后记：
SMART 可以提醒你，但不能帮你做备份。要真正的让SMART为你服务，应该好好读写smartd & smartd.conf 的注释, 让其后台程序在一定情况下提醒你(mail)有些关键值达到了危险区域, 以上给出的几个命令是在你开始感到情况不妙的时候进行的手工测试。
