SMARTCTL(8)

NAME
smartctl - Control and Monitor Utility for SMART Disks

SYNOPSIS
smartctl [options] device

DESCRIPTION
smartctl controls the Self-Monitoring, Analysis and Reporting Technology (SMART) system built into many ATA-3 and later ATA, IDE and SCSI-3 hard drives. The purpose of SMART is to monitor the reliability of the hard drive and predict drive failures, and to carry out different types of drive self-tests. This version of smartctl is compatible with ATA/ATAPI-5 and earlier standards (see REFERENCES below) smartctl is a command line utility designed to perform SMART tasks such as printing the SMART self-test and error logs, and enabling and disabling SMART automatic testing. Note: if the user issues a SMART command that is (apparently) not implemented by the device, smartctl will print a warning message but issue the command anyway (see the -T, --tolerance option below). This should not cause problems: on most devices, unimplemented SMART commands issued to a drive are ignored and/or return an error. smartctl also provides support for polling TapeAlert messages from SCSI tape drives and changers. The user must specify the device to be controlled or interrogated as the final argument to smartctl. ATA devices use the form "/dev/hd*" and SCSI devices use the form "/dev/sd*". For SCSI Tape Drives and Changers with TapeAlert support use the devices "/dev/nst*" and "/dev/sg*". More general paths may also be specified. smartctl will attempt to guess the device type, but the '-d' option can be used to specify a device type of ATA or SCSI if required. Note that the printed output of smartctl displays most numerical values in base 10 (decimal), but some values are displayed in base 16 (hexidecimal). To distinguish them, the base 16 values are always displayed with a leading 0x for example: "0xff". This man page follows the same convention.

OPTIONS

The options are grouped below into several categories. smartctl will execute the corresponding commands in the order: INFORMATION, ENABLE/DISABLE, DISPLAY DATA, RUN/ABORT TESTS. SCSI devices only accept the options -h, -?, -V, -i, -a, -d, -s, -H, -t, -C, -l selftest, -l error and -X. TapeAlert devices only accept the options -h, -?, -V, -i, -a, -d, -s, -t, -l selftest, -l error and -H. Long options are not supported on all systems. Use 'smartctl -h' to see the available options.

SHOW INFORMATION:

-h, --help, --usage
    Prints a usage message to STDOUT and exits.

-?  Same as -h.

-V, --version, --copyright, --license
    Prints version, copyright, license, home page and CVS-id information for your copy of smartctl to STDOUT and then exits. Please include this information if you are reporting bugs or problems.

-i, --info
    Prints the device model number, serial number, firmware version, and ATA Standard version/revision information. Says if the device supports SMART, and if so, whether SMART support is currently enabled or disabled.

-a, --all
    Prints all SMART information about the disk or TapeAlert information about the tape drive or changer. This is equivalent to '-H -i -c -A -l error -l selftest' (for SCSI, '-H -i -l error -l selftest').

RUN-TIME BEHAVIOR:

-q TYPE, --quietmode=TYPE
    Specifies that smartctl should run in one of the two quiet modes described here. The valid arguments to this option are: errorsonly - only print: For the '-l error' option, if nonzero, the number of errors recorded in the SMART error log and the power-on time when they occurred; For the '-l selftest' option, errors recorded in the device self-test log; For the '-H' option, SMART "disk failing" status or device Attributes (pre-failure or usage) which failed either now or in the past; For the '-A' option, device Attributes (pre-failure or usage) which failed either now or in the past. silent - print no output. The only way to learn about what was found is to use the exit status of smartctl (see RETURN VALUES below).

-d TYPE, --device=TYPE
    Specifies the type of the device. The valid arguments to this option are ata, scsi, and 3ware,N. If this option is not used then smartctl will attempt to guess the device type from the device name. To look at ATA disks behind 3ware SCSI RAID controllers, use syntax such as:
    smartctl -a -d 3ware,2 /dev/sda
    where in the argument 3ware,N, the integer N is the disk number within the 3ware ATA RAID controller. The allowed values of N are from 0 to 15 inclusive. Note that older 3w-xxxx drivers do not pass the 'Enable Autosave' (-S on) and 'Enable Automatic Offline' (-o on) commands to the disk, and produce these types of harmless syslog error messages instead: '3w-xxxx: tw_ioctl(): Passthru size (123392) too big'. This can be fixed by upgrading to version 1.02.00.037 or later of the 3w-xxxx driver, or by applying a patch to older versions. See http://smartmontools.sourceforge.net/ for instructions.

-T TYPE, --tolerance=TYPE
    Specifies how tolerant smartctl should be of SMART command failures. The valid arguments to this option are: normal - exit on failure of a mandatory SMART command, and ignore failures of optional SMART commands. This is the default. It can lead to messages like 'Feature X not implemented', followed shortly by 'Error: unable to enable Feature X'. On some devices, giving unimplemented optional SMART commands doesn't even cause an error. This can result in misleading smartctl messages such as 'Feature X not implemented', followed shortly by 'Feature X: enabled'. In most such cases, contrary to the final message, the Feature is not enabled. conservative - exit on failure of any SMART command. permissive - ignore failures of any SMART commands. Here "mandatory" means "required by the ATA/ATAPI-5 Specification if the device implements the SMART command set" and "optional" means "not required by the ATA/ATAPI-5 Specification even if the device implements the SMART command set." The 'mandatory' SMART commands are: (1) Enable/Disable Attribute Autosave, (2) Enable/Disable SMART, and (3) SMART Return Status.

-b TYPE, --badsum=TYPE
    Specifies the action smartctl should take if a checksum error is detected in the: (1) Device Identity Structure, (2) SMART Self-Test Log Structure, (3) SMART Attribute Value Structure, (4) SMART Attribute Threshold Structure, or (5) ATA Error Log Structure. The valid arguments to this option are: warn - report the incorrect checksum but carry on in spite of it. This is the default. exit - exit smartctl. ignore - continue silently without issuing a warning.

-r TYPE, --report=TYPE
    Intended primarily to help smartmontools developers understand the behavior of smartmontools on non-conforming or poorly conforming hardware. This option reports details of smartctl transactions with the device. The option can be used multiple times. When used just once, it shows a record of the ioctl() transactions with the device. When used more than once, the detail of these ioctl() transactions are reported in greater detail. The valid arguments to this option are: ioctl - report all ioctl() transactions. ataioctl - report only ioctl() transactions with ATA devices. scsiioctl - report only ioctl() transactions with SCSI devices. Invoking this once shows the SCSI commands in hex and the corresponding status. Invoking it a second time adds a hex listing of the first 64 bytes of data send to, or received from the device. Any argument may include a positive integer to specify the level of detail that should be reported. The argument should be followed by a comma then the integer with no spaces. For example, ataioctl,2 The default level is 1, so '-r ataioctl,1' and '-r ataioctl' are equivalent.

SMART FEATURE ENABLE/DISABLE COMMANDS:

    Note: if multiple options are used to both enable and disable a feature, then both the enable and disable commands will be issued. The enable command will always be issued before the corresponding disable command.

-s VALUE, --smart=VALUE
    Enables or disables SMART on device. The valid arguments to this option are on and off. Note that the command '-s on' (perhaps used with with the '-o on' and '-S on' options) should be placed in a start-up script for your machine, for example in rc.local or rc.sysinit. In principle the SMART feature settings are preserved over power-cycling, but it doesn't hurt to be sure. It is not necessary (or useful) to enable SMART to see the TapeAlert messages.

-o VALUE, --offlineauto=VALUE
    Enables or disables SMART automatic offline test, which scans the drive every four hours for disk defects. This command can be given during normal system operation. The valid arguments to this option are on and off. Note that the SMART automatic offline test command is listed as 'Obsolete' in every version of the ATA and ATA/ATAPI Specifications. It was originally part of the SFF-8035i Revision 2.0 specification, but was never part of any ATA specification. However it is implemented and used by many vendors. [Good documentation can be found in IBM's Official Published Disk Specifications. For example the IBM Travelstar 40GNX Hard Disk Drive Specifications (Revision 1.1, 22 April 2002, Publication # 1541, Document S07N-7715-02) page 164. You can also read the SFF-8035i Specification -- see REFERENCES below.] You can tell if automatic offline testing is supported by seeing if this command enables and disables it, as indicated by the SMART capabilities (displayed with '-c'). SMART provides three basic categories of testing. The first category, called 'online' testing, has no effect on the performance of the device. It is turned on by the '-s on' option. The second category of testing is called 'offline' testing. This type of test can, in principle, degrade the device performance. The '-o on' option causes this offline testing to be carried out, automatically, on a regular scheduled basis. Normally, the disk will suspend offline testing while disk accesses are taking place, and then automatically resume it when the disk would otherwise be idle, so in practice it has little effect. Note that a one-time offline test can also be carried out immediately upon receipt of a user command. See the '-t offline' option below, which causes a one-time offline test to be carried out immediately. Any errors detected in automatic or immediate offline testing are reflected in the values of the SMART Attributes; some types of errors may also appear in the SMART error log. These are visible with the '-A' and '-l error' options respectively. Some SMART attribute values are updated only during off-line data collection activities; the rest are updated during normal operation of the device or during both normal operation and off-line testing. The Attribute value table produced by the '-A' option indicates this in the UPDATED column. Attributes of the first type are labeled "Offline" and Attributes of the second type are labeled "Always". The third category of testing is the 'self' testing. This third type of test is only performed (immediately) when a command to run it is issued. The '-t' and '-X' options can be used to carry out and abort such self-tests; please see below for further details. Any errors detected in the self testing will be shown in the SMART self-test log, which can be examined using the '-l selftest' option. Note: in this manual page, the word Test is used in connection with the second category just described, e.g. for the 'offline' testing. The words Self-test are used in connection with the third category.

-S VALUE, --saveauto=VALUE
    Enables or disables SMART autosave of device vendor-specific Attributes. The valid arguments to this option are on and off. Note that this feature is preserved across disk power cycles, so you should only need to issue it once.

SMART READ AND DISPLAY DATA OPTIONS:

-H, --health
    Check: Ask the device to report its SMART health status or pending TapeAlert messages. SMART status is based on information that it has gathered from online and offline tests, which were used to determine/update its SMART vendor-specific Attribute values. TapeAlert status is obtained by reading the TapeAlert log page. If the device reports failing health status, this means either that the device has already failed, or that it is predicting its own failure within the next 24 hours. If this happens, use the '-a' option to get more information, and get your data off the disk and someplace safe as soon as you can.

-c, --capabilities
    Prints only the generic SMART capabilities. These show what SMART features are implemented and how the device will respond to some of the different SMART commands. For example it shows if the device logs errors, if it supports offline surface scanning, and so on. If the device can carry out self-tests, this option also shows the estimated time required to run those tests. Note that the time required to run the Self-tests (listed in minutes) are fixed. However the time required to run the Immediate Offline Test (listed in seconds) is variable. This means that if you issue a command to perform an Immediate Offline test with the '-t offline' option, then the time may jump to a larger value and then count down as the Immediate Offline Test is carried out. Please see REFERENCES below for further information about the the flags and capabilities described by this option.

-A, --attributes
    Prints only the vendor specific SMART Attributes. The Attributes are numbered from 1 to 253 and have specific names and ID numbers. For example Attribute 12 is 'power cycle count': how many times has the disk been powered up. Each Attribute has a 'Raw' value, printed under the heading 'RAW_VALUE', and a 'Normalized' value printed under the heading 'VALUE'. [Note: smartctl prints these values in base-10.] In the example just given, the 'Raw Value' for Attribute 12 would be the actual number of times that the disk has been power-cycled, for example 365 if the disk has been turned on once per day for exactly one year. Each vendor uses their own algorithm to convert this Raw value to a Normalized value in the range from 1 to 254. Note that smartctl only reports the different Attribute values and thresholds. It does not carry out the conversion between 'Raw' and 'Normalized' values. Note that the conversion from 'Raw' value to a quantity with physical units is not specified by the SMART standard. In most cases, the values printed by smartctl are sensible. For example the temperature Attribute generally has its raw value equal to the temperature in Celsius. However in some cases vendors use unusual conventions. For example the Hitachi disk on my laptop reports its power-on hours in minutes, not hours. Some IBM disks track three temperatures rather than one, in their raw values. And so on. Each Attribute also has a Threshold value (whose range is 0 to 255) which is printed under the heading 'THRESH'. If the Normalized value is less than or equal to the Threshold value, then the Attribute is said to have failed. If the Attribute is a pre-failure Attribute, then disk failure is imminent. Each Attribute also has a 'Worst' value shown under the heading 'WORST'. This is the smallest (closest to failure) value that the disk has recorded at any time during its lifetime when SMART was enabled. [Note however that some vendors will have firmware which will increase the 'Worst' value for some "rate-type" Attributes.] The Attribute table printed out by smartctl also shows the 'TYPE' of the Attribute. Pre-failure Attributes are ones which, if less than or equal to their threshold values, indicate pending disk failure. Old age, or usage Attributes, are ones which indicate end-of-product life from old-age or normal aging and wearout, if the Attribute value is less than or equal to the threshold. If the Attribute's current Normalized value is <= threshold, then the 'WHEN_FAILED' column will display 'FAILED NOW!'. If not, but the worst recorded value is <= threshold, then this column will display 'In the past'. The table column labeled 'UPDATED' shows if the SMART Attribute values are updated during both normal operation and off-line testing, or only during offline testing. The former are labeled 'Always' and the latter are labeled 'Offline'. So to summarize: the 'Raw' values are the ones that might have a real physical interpretation, such as 'Temperature Celsius', 'Hours', or 'Start-Stop Cycles'. Each manufacturer converts these, using their detailed knowledge of the disk's operations and failure modes, to Normalized Attribute values in the range 1-254. The worst (lowest measured) of these Normalized Attribute values is stored on the disk, along with a Threshold value that the manufacturer has determined will indicate that the disk is going to fail, or that it has exceeded its design age or aging limit. smartctl does not calculate any of these values, it merely reports them from the SMART data on the disk. Note that starting with ATA/ATAPI-4, revision 4, the meaning of these Attribute fields has been made entirely vendor-specific. However most ATA/ATAPI-5 disks seem to respect their meaning, so we have retained the option of printing the Attribute values.

-l TYPE, --log=TYPE
    Prints either the SMART error log or the SMART self-test log. The valid arguments to this option are: error - prints only the SMART error log. SMART disks maintain a log of the most recent five non-trivial errors. For each of these errors, the disk power-on lifetime at which the error occurred is recorded, as is the device status (idle, standby, etc) at the time of the error. Finally, up to the last five commands that preceded the error are also recorded, along with a timestamp measured in seconds from the start of the corresponding power cycle. [Note: this time stamp wraps after 2^32 milliseconds, or 49 days 17 hours 2 minutes and 47.296 seconds.] The key ATA disk registers are also recorded in the log. The final column of the error log is a text-string description of the ATA command defined by the Command Register (CR) and Feature Register (FR) values. Commands that are obsolete in the most current (ATA-7) spec are listed like this: READ LONG (w/ retry) [OBS-4], indicating that the command became obsolete with or in the ATA-4 specification. Similarly, the notation [RET-N] is used to indicate that a command was retired in the ATA-N specification. Some commands are not defined in any version of the ATA specification but are in common use nonetheless; these are marked [NS], meaning non-standard. The ATA Specification (ATA-5 Revision 1c, Section 8.41.6.8.2 to be precise) says:
    "Error log structures shall include UNC errors, IDNF errors for which the address requested was valid, servo errors, write fault errors, etc. Error log data structures shall not include errors attributed to the receipt of faulty commands such as command codes not implemented by the device or requests with invalid parameters or invalid addresses."
    The definitions of these terms are:
    UNC (UNCorrectable): data is uncorrectable.
    IDNF (ID Not Found): user-accessible address could not be found. For READ LOG type commands this also can indicate that a device data log structure checksum was incorrect. error [SCSI] - prints the error counter log pages for reads, write and verifies. The verify row is only output if it has an element other than zero. selftest - prints only the SMART self-test log. The disk maintains a log showing the results of the self tests, which can be run using the '-t' option described below. For each of the most recent twenty-one self-tests, the log shows the type of test (short or extended, off-line or captive) and the final status of the test. If the test did not complete successfully, then the percentage of the test remaining is shown. The time at which the test took place, measured in hours of disk lifetime, is also printed. If any errors were detected, the Logical Block Address (LBA) of the first error is printed in hexadecimal notation. selftest [SCSI] - the self-test log for a SCSI device has a slightly different format than for an ATA device. For each of the most recent twenty self-tests, it shows the type of test and the status (final or in progress) of the test. SCSI standards use the terms 'foreground' and 'background' (rather than ATA's corresponding 'captive' and 'off-line') and 'short' and 'long' (rather than ATA's corresponding 'short' and 'extended') to describe the type of the test. The printed segment number is only relevant when a test fails in the third or later test segment. It identifies the test that failed and consists of either the number of the segment that failed during the test, or the number of the test that failed and the number of the segment in which the test was run, using a vendor-specific method of putting both numbers into a single byte. The Logical Block Address (LBA) of the first error is printed in hexadecimal notation. If provided, the SCSI Sense Key (SK), Additional Sense Code (ASC) and Additional Sense Code Qualifier (ASQ) are also printed. The self tests can be run using the '-t' option described below (using the ATA test terminology). directory - if the device supports the General Purpose Logging feature set (ATA-6 and ATA-7 only) then this prints the Log Directory (the log at address 0). The Log Directory shows what logs are available and their length in sectors (512 bytes). The contents of the logs at address 1 [Summary SMART error log] and at address 6 [SMART self-test log] may be printed using the previously-described error and selftest arguments to this option. [Please note: this is a new, experimental feature. We would like to add support for printing the contents of extended and comprehensive SMART self-test and error logs. If your disk supports these, and you would like to assist, please contact the smartmontools developers.]

-v N,OPTION, --vendorattribute=N,OPTION
    Sets a vendor-specific display OPTION for Attribute N. This option may be used multiple times. Valid arguments to this option are: help - Prints (to STDOUT) a list of all valid arguments to this option, then exits. 9,minutes - Raw Attribute number 9 is power-on time in minutes. Its raw value will be displayed in the form 'Xh+Ym'. Here X is hours, and Y is minutes in the range 0-59 inclusive. Y is always printed with two digits, for example '06' or '31' or '00'. 9,seconds - Raw Attribute number 9 is power-on time in seconds. Its raw value will be displayed in the form 'Xh+Ym+Zs'. Here X is hours, Y is minutes in the range 0-59 inclusive, and Z is seconds in the range 0-59 inclusive. Y and Z are always printed with two digits, for example '06' or '31' or '00'. 9,halfminutes - Raw Attribute number 9 is power-on time, measured in units of 30 seconds. This format is used by some Samsung disks. Its raw value will be displayed in the form 'Xh+Ym'. Here X is hours, and Y is minutes in the range 0-59 inclusive. Y is always printed with two digits, for example '06' or '31' or '00'. 9,temp - Raw Attribute number 9 is the disk temperature in Celsius. 192,emergencyretractcyclect - Raw Attribute number 192 is the Emergency Retract Cycle Count. 193,loadunload - Raw Attribute number 193 contains two values. The first is the number of load cycles. The second is the number of unload cycles. The difference between these two values is the number of times that the drive was unexpectedly powered off (also called an emergency unload). As a rule of thumb, the mechanical stress created by one emergency unload is equivalent to that created by one hundred normal unloads. 194,10xCelsius - Raw Attribute number 194 is ten times the disk temperature in Celsius. This is used by some Samsung disks (example: model SV1204H with RK100-13 firmware). 194,unknown - Raw Attribute number 194 is NOT the disk temperature, and its interpretation is unknown. This is primarily useful for the -P (presets) option. 198,offlinescanuncsectorct - Raw Attribute number 198 is the Offline Scan UNC Sector Count. 200,writeerrorcount - Raw Attribute number 200 is the Write Error Count. 201,detectedtacount - Raw Attribute number 201 is the Detected TA Count. 220,temp - Raw Attribute number 220 is the disk temperature in Celsius. Note: a table of hard drive models, listing which Attribute corresponds to temperature, can be found at: http://coredump.free.fr/linux/hddtemp.db N,raw8 - Print the Raw value of Attribute N as six 8-bit unsigned base-10 integers. This may be useful for decoding the meaning of the Raw value. The form 'N,raw8' prints Raw values for ALL Attributes in this form. The form (for example) '123,raw8' only prints the Raw value for Attribute 123 in this form. N,raw16 - Print the Raw value of Attribute N as three 16-bit unsigned base-10 integers. This may be useful for decoding the meaning of the Raw value. The form 'N,raw16' prints Raw values for ALL Attributes in this form. The form (for example) '123,raw16' only prints the Raw value for Attribute 123 in this form. N,raw48 - Print the Raw value of Attribute N as a 48-bit unsigned base-10 integer. This may be useful for decoding the meaning of the Raw value. The form 'N,raw48' prints Raw values for ALL Attributes in this form. The form (for example) '123,raw48' only prints the Raw value for Attribute 123 in this form.

-F TYPE, --firmwarebug=TYPE
    Modifies the behavior of smartctl to compensate for some known and understood device firmware bug. The valid arguments to this option are: none Assume that the device firmware obeys the ATA specifications. This is the default. samsung In some Samsung disks (example: model SV4012H Firmware Version: RM100-08) some of the two- and four-byte quantities in the SMART data structures are byte-swapped (relative to the ATA specification). Enabling this option tells smartctl to evaluate these quantities in byte-reversed order. Some signs that your disk needs this option are (1) no self-test log printed, even though you have run self-tests; (2) very large numbers of ATA errors reported in the ATA erorr log; (3) strange and impossible values for the ATA error log timestamps.

-P TYPE, --presets=TYPE
    Specifies whether smartctl should use any preset options that are available for this drive. By default, if the drive is recognized in the smartmontools database, then the presets are used. smartctl can automatically set appropriate options for known drives. For example, the Maxtor 4D080H4 uses Attribute 9 to stores power-on time in minutes whereas most drives use that Attribute to store the power-on time in hours. The command-line option '-v 9,minutes' ensures that smartctl correctly interprets Attribute 9 in this case, but that option is preset for the Maxtor 4D080H4 and so need not be specified by the user on the smartctl command line. The argument show will show any preset options for your drive and the argument showall will show all known drives in the smartmontools database, along with their preset options. If there are no presets for your drive and you think there should be (for example, a -v or -F option is needed to get smartctl to display correct values) then please contact the smartmontools developers so that this information can be added to the smartmontools database. Contact information is at the end of this man page. The valid arguments to this option are: use - if a drive is recognized, then use the stored presets for it. This is the default. Note that presets will NOT over-ride additional Attribute interpretation ('-v N,something') command-line options. ignore - do not use presets. show - show if the drive is recognized in the database, and if so, its presets, then exit. showall - list all recognized drives, and the presets that are set for them, then exit.

SMART RUN/ABORT OFFLINE TEST AND SELF-TEST OPTIONS:

-t TEST, --test=TEST
    Executes TEST immediately. The '-C' option can be used in conjunction with this option to run the short or long (and also for ATA devices, conveyance) self-tests in captive mode (known as 'foreground mode' for SCSI devices). Note that only one test can be run at a time, so this option should only be used once per command line. The valid arguments to this option are: offline - runs SMART Immediate Offline Test. This immediately starts the test described above. This command can be given during normal system operation. The effects of this test are visible only in that it updates the SMART Attribute values, and if errors are found they will appear in the SMART error log, visible with the '-l error' option. [In the case of SCSI devices runs the default self test in foreground. No entry is placed in the self test log.] If the '-c' option to smartctl shows that the device has the "Suspend Offline collection upon new command" capability then you can track the progress of the Immediate Offline test using the '-c' option to smartctl. If the '-c' option show that the device has the "Abort Offline collection upon new command" capability then most commands will abort the Immediate Offline Test, so you should not try to track the progress of the test with '-c', as it will abort the test. short - runs SMART Short Self Test (usually under ten minutes). [Note: in the case of SCSI devices, this command option runs the 'Background short' self-test.] This command can be given during normal system operation (unless run in captive mode - see the '-C' option below). This is a test in a different category than the immediate or automatic offline tests. The 'Self' tests check the electrical and mechanical performance as well as the read performance of the disk. Their results are reported in the Self Test Error Log, readable with the '-l selftest' option. Note that on some disks the progress of the self-test can be monitored by watching this log during the self-test; with other disks use the '-c' option to monitor progress. long - runs SMART Extended Self Test (tens of minutes). [Note: in the case of SCSI devices, this command option runs the 'Background long' self-test.] This is a longer and more thorough version of the Short Self Test described above. Note that this command can be given during normal system operation (unless run in captive mode - see the '-C' option below). conveyance - [ATA ONLY] runs a SMART Conveyance Self Test (minutes). This self-test routine is intended to identify damage incurred during transporting of the device. This self-test routine should take on the order of minutes to complete. Note that this command can be given during normal system operation (unless run in captive mode - see the '-C' option below).

-C, --captive
    Runs self-tests in captive mode. This has no effect with '-t offline' or if the '-t' option is not used. [Note: in the case of SCSI devices, this command option runs the self-test in 'Foreground' mode.] WARNING: Tests run in captive mode may busy out the drive for the length of the test. Only run captive tests on drives without any mounted partitions!

-X, --abort
    Aborts non-captive SMART Self Tests. Note that this command will abort the Offline Immediate Test routine only if your disk has the "Abort Offline collection upon new command" capability.

EXAMPLES
smartctl -a /dev/hda
Print all SMART information for drive /dev/hda (Primary Master).

smartctl -s off /dev/hdd
Disable SMART on drive /dev/hdd (Secondary Slave).

smartctl --smart=on --offlineauto=on --saveauto=on /dev/hda
Enable SMART on drive /dev/hda, enable automatic offline testing every four hours, and enable autosaving of SMART Attributes. This is a good start-up line for your system's init files. You can issue this command on a running system.

smartctl -t long /dev/hdc
Begin an extended self-test of drive /dev/hdc. You can issue this command on a running system. The results can be seen in the self-test log visible with the '-l selftest' option after it has completed.

smartctl -s on -t offline /dev/hda
Enable SMART on the disk, and begin an immediate offline test of drive /dev/hda. You can issue this command on a running system. The results are only used to update the SMART Attributes, visible with the '-A' option. If any device errors occur, they are logged to the SMART error log, which can be seen with the '-l error' option.

smartctl -A -v 9,minutes /dev/hda
Shows the vendor Attributes, when the disk stores its power-on time internally in minutes rather than hours.

smartctl -q errorsonly -H -l selftest /dev/hda
Produces output only if the device returns failing SMART status, or if some of the logged self-tests ended with errors.

smartctl -q silent -a /dev/hda
Examine all SMART data for device /dev/hda, but produce no printed output. You must use the exit status (the $? shell variable) to learn if any Attributes are out of bound, if the SMART status is failing, if there are errors recorded in the self-test log, or if there are errors recorded in the disk error log.

smartctl -a -d 3ware,0 /dev/sda
Examine all SMART data for the first ATA disk connected to a 3ware RAID controller card.

smartctl -t short -d 3ware,3 /dev/sdb
Start a short self-test on the fourth ATA disk connected to the 3ware RAID controller card which is the second SCSI device /dev/sdb.

RETURN VALUES
The return values of smartctl are defined by a bitmask. For the moment this only works on ATA disks. The different bits in the return value are as follows:

Bit 0:
    Command line did not parse.

Bit 1:
    Device open failed, or device did not return an IDENTIFY DEVICE structure.

Bit 2:
    Some SMART command to the disk failed, or there was a checksum error in a SMART data structure (see '-b' option above).

Bit 3:
    SMART status check returned "DISK FAILING".

Bit 4:
    SMART status check returned "DISK OK" but we found prefail Attributes <= threshold.

Bit 5:
    SMART status check returned "DISK OK" but we found that some (usage or prefail) Attributes have been <= threshold at some time in the past.

Bit 6:
    The device error log contains records of errors.

Bit 7:
    The device self-test log contains records of errors. To test within the shell for whether or not the different bits are turned on or off, you can use the following type of construction (this is bash syntax):
    smartstat=$(($? & 8))
    This looks at only at bit 3 of the exit status $? (since 8=2^3). The shell variable $smartstat will be nonzero if SMART status check returned 'disk failing' and zero otherwise.

NOTES
The TapeAlert log page flags are cleared for the initiator when the page is read. This means that each alert condition is reported only once by smartctl for each initiator for each activation of the condition.

AUTHOR
Bruce Allen smartmontools-support@lists.sourceforge.net
University of Wisconsin - Milwaukee Physics Department

CREDITS
This code was derived from the smartsuite package, written by Michael Cornwell, and from the previous ucsc smartsuite package. It extends these to cover ATA-5 disks. This code was originally developed as a Senior Thesis by Michael Cornwell at the Concurrent Systems Laboratory (now part of the Storage Systems Research Center), Jack Baskin School of Engineering, University of California, Santa Cruz. http://ssrc.soe.ucsc.edu/ .

HOME PAGE FOR SMARTMONTOOLS:
Please see the following web site for updates, further documentation, bug reports and patches:
http://smartmontools.sourceforge.net/

SEE ALSO:
smartd (8)

REFERENCES FOR SMART
If you would like to understand better how SMART works, and what it does, a good place to start is Section 8.41 of the 'AT Attachment with Packet Interface-5' (ATA/ATAPI-5) specification. This documents the SMART functionality which the smartmontools utilities provide access to. You can find Revision 1 of this document at http://www.t13.org/project/d1321r1c.pdf .
Future versions of the specifications (ATA/ATAPI-6 and ATA/ATAPI-7), and later revisions (2, 3) of the ATA/ATAPI-5 specification are available from http://www.t13.org/#FTP_site .
The functioning of SMART was originally defined by the SFF-8035i revision 2 and the SFF-8055i revision 1.4 specifications. These are publications of the Small Form Factors (SFF) Committee. Links to these documents may be found in the References section of the smartmontools home page at http://smartmontools.sourceforge.net/ .

CVS ID OF THIS PAGE:
$Id: smartctl.8,v 1.84 2003/08/20 06:00:16 pervalidus Exp $