Formatting and initialization of device mirrors using initialization indicators

A data storage system comprising:

• a disk adapter servicing a device in said data storage system;
• a processor in said data storage system which receives commands to be executed by said data storage system;
• wherein said data storage system includes:
• code that receives a command requesting processing which includes initializing said device;
• code that receives a second command inquiring regarding a status of the command;
• code that, in response to receiving the second command after said command, performs processing including monitoring the status of the command by monitoring status information indicating whether processing for the command has completed and returning a status message in accordance with the status information, said status information including one or more initialization indicators and an online indicator indicating whether the device is available;
• code that sets said one or more initialization indicators each associated with a portion of said device indicating that said portion is to be initialized;
• code that receives a data request which is a write data request to write data to a first portion of said device;
• code that, upon receiving said data request, initializes said first portion prior to processing said data request if a first initialization indicator associated with said first portion is set, wherein said code that initializes performs initialization in response to receiving said data request;
• code that, after completing said initialization of said first portion, performs processing for said write data request including clearing said first initialization indicator, storing said write data request to a cache slot to be destaged at a later point in time, and setting a write pending bit in said cache slot;
• and
• code that returns a status indicating completion of the command, prior to initializing all portions of said device and after all initialization indicators associated with said device have been set, wherein a value of one of said initialization indicators corresponding to a portion directly indicates an initialization status for said portion.

A computer program product for initializing a device in a data storage system comprising code for:

• receiving a command requesting processing which includes initializing said device;
• receiving a second command inquiring regarding a status of the command;
• in response to receiving the second command after said command, performing processing including monitoring the status of the command by monitoring status information indicating whether processing for the command has completed and returning a status message in accordance with the status information, said status information including one or more initialization indicators and an online indicator indicating whether the device is available;
• setting said one or more initialization indicators each associated with a portion of said device indicating that said portion is to be initialized, wherein a value of one of said initialization indicators corresponding to a portion directly indicates an initialization status for said portion;
• receiving a subsequent data request which is a write data request to write data to a first portion of said device;
• prior to performing said subsequent data request, initializing said first portion if a first initialization indicator associated with said first portion is set, wherein said initializing is performed in response to receiving said subsequent data request;
• and
• after completing said initializing said first portion, performing processing for said write data request including storing said write data of said write data request to a cache slot to be destaged at a later point in time and setting a write pending bit in said cache slot.