Smart Disable Operations Subcommand D9h

11.42.1.9SMART Disable Operations (Subcommand D9h)

This subcommand disables all SMART capabilities within the device including the device‟s attribute autosave feature. After receipt of this subcommand the device disables all SMART operations. Non self-preserved Attribute Values will no longer be monitored. The state of SMART (either enabled or disabled) is preserved by the device across power cycles.

Upon receipt of the SMART Disable Operations subcommand from the host, the device disables SMART capabilities and functions, and then saves any updated Attribute Values to the Attribute Data sector.

After receipt of the device of the SMART Disable Operations subcommand from the host, all other SMART subcommands – with the exception of SMART Enable Operations – are disabled, and invalid and will be aborted by the device (including the SMART Disable Operations subcommand), returning the error code as specified in 0 on the page 221.

Any Attribute Values accumulated and saved to volatile memory prior to receipt of the SMART Disable Operations command will be preserved in the device‟s Attribute Data Sectors. If the device is re-enabled, these Attribute Values will be updated, as needed, upon receipt of a SMART Read Attribute Values or SMART Save Attribute Values command.

11.42.1.10SMART Return Status (Subcommand Dah)

This command is used to communicate the reliability status of the device to the host‟s request. Upon receipt of the SMART Return Status subcommand the device saves any updated Pre-failure type Attribute Values to the reserved sector and compares the updated Attribute Values to the Attribute Thresholds.

If the device does not detect a Threshold Exceeded Condition, the device loads 4Fh into the Cylinder Low register, C2h into the Cylinder High register.

If the device detects a Threshold Exceeded Condition, the device loads F4h into the Cylinder Low register, 2Ch into the Cylinder High register.

11.42.1.11SMART Enable/Disable Automatic Off-Line (Subcommand DBh)

This subcommand enables and disables the optional feature that causes the device to perform the set of off-line data collection activities that automatically collect attribute data in an off-line mode and then save this data to the device‟s non-volatile memory. This subcommand may either cause the device to automatically initiate or resume performance of its off-line data collection activities or cause the automatic off-line data collection feature to be disabled.

A value of zero written by the host into the device‟s Sector Count Register before issuing this subcommand shall cause the feature to be disabled. Disabling this feature does not preclude the device from saving attribute values to non-volatile memory during some other normal operation such as during a power-on or power-off sequence or during an error recovery sequence.

A value of F8h written by the host into the device‟s Sector Count Register before issuing this subcommand shall cause this feature to be enabled. Any other non-zero value written by the host into this register before issuing this subcommand is vender specific and will not change the current Automatic Off-Line Data Collection, but the device may respond with the error code specified in 0 on the page.221

Hitachi hard disk drive specifications

208 HCS721016CLA382, HCS721050CLA382, HCS721025CLA382, HDP725050GLA360, HUA722050CLA330/1 specifications

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The HDS721032CLA362 and HDS721032CLA662 share many similarities and are both designed for budget-conscious consumers. With a capacity of 320GB and a 7200 RPM, they offer efficient storage solutions for everyday tasks. The 32MB cache buffer enables efficient caching of frequently accessed files, providing a smooth experience for users.

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