Host-controlled garbage collection

Abstract

In an array of solid-state drives (SSDs), SSDs in the array are each configured to initiate generation of additional erased memory blocks when an initiation command is received from a host or when the number of erased memory blocks in the SSD falls below a minimum threshold of erased memory blocks for the SSD. The minimum threshold value may be adjusted by the host.

I claim: 
     
         1 . A data storage device comprising:
 a non-volatile solid-state storage device including a plurality of erasable blocks; and   a control circuit configured to set a condition to trigger a process for generating erased blocks in the non-volatile solid-state storage device based on a value received from a host that is connected to the data storage device, and upon the set condition being met, initiate the process for generating erased blocks in the non-volatile solid-state storage device.   
     
     
         2 . The data storage device according to  claim 1 , wherein
 the control circuit is further configured to set a second condition to stop the process based on a second value received from the host, and upon the set second condition being met, stop the process for generating erased blocks in the non-volatile solid-state storage device.   
     
     
         3 . The data storage device according to  claim 1 , wherein
 the control circuit is further configured to send to the host a notification that the set condition is about to be met, before the set condition is met.   
     
     
         4 . The data storage device according to  claim 1 , wherein
 the control circuit is further configured to perform an operation of returning a number of erased blocks that are currently available in the non-volatile solid-state storage device, in response to an inquiry from the host.   
     
     
         5 . The data storage device according to  claim 4 , wherein
 the control circuit is further configured to enable the operation based on a system interface command received from the host, and   the control circuit performs the operation in response to the inquiry when the operation is enabled, and does not perform the operation in response to the inquiry when the operation is disabled.   
     
     
         6 . The data storage device according to  claim 5 , wherein
 the system interface command comprises one of a serial advanced technology attachment (SATA) set features command, a serial attached small computer system interface (SAS) mode select command, or a non-volatile memory express (NVMe) set features command.   
     
     
         7 . The data storage device according to  claim 1 , wherein
 the control circuit is further configured to initiate the process for generating erased blocks in the non-volatile solid-state storage device in response to an initiation command from the host, regardless of the set condition being met.   
     
     
         8 . The data storage device according to  claim 1 , wherein
 the condition includes at least a state that the number of erased blocks in the non-volatile solid-state storage device is less than a threshold value.   
     
     
         9 . The data storage device according to  claim 1 , wherein
 the data storage device is one of a plurality of data storage devices that form a data storage array coupled to the host.   
     
     
         10 . The data storage device according to  claim 1 , wherein
 the process for generating erased blocks in the non-volatile solid-state storage device comprises copying selectively valid data in first one or more erasable blocks of the non-volatile solid-state storage device to second one or more erasable blocks of the non-volatile solid-state storage device, and erasing data in the first one or more erasable blocks.   
     
     
         11 . A data storage system comprising
 a host; and   a data storage device connected to the host and including a non-volatile solid-state storage device including a plurality of erasable blocks and a control circuit, wherein   the host is configured to send a value to the data storage device, and   the control circuit is configured to set a condition to trigger a process for generating erased blocks in the non-volatile solid-state storage device based on the value received from the host, and upon the set condition being met, initiate the process for generating erased blocks in the non-volatile solid-state storage device.   
     
     
         12 . The data storage system according to  claim 11 , wherein
 the host is further configured to send a second value to the data storage device, and   the control circuit is further configured to set a second condition to stop the process based on the second value received from the host, and upon the set second condition being met, stop the process for generating erased blocks in the non-volatile solid-state storage device.   
     
     
         13 . The data storage system according to  claim 11 , wherein
 the host is further configured to send a command to the data storage device, the command causing the control circuit to send to the host a notification that the set condition is about to be met, before the set condition is met.   
     
     
         14 . The data storage system according to  claim 11 , wherein
 the host is further configured to send an inquiry to the data storage device, the inquiry causing the control circuit to perform an operation of returning a number of erased blocks that are currently available in the non-volatile solid-state storage device, in response to the inquiry.   
     
     
         15 . The data storage system according to  claim 14 , wherein
 the host is further configured to send, to the data storage device, a system interface command that enables the operation,   the control circuit performs the operation in response to the inquiry when the operation is enabled, and does not perform the operation in response to the inquiry when the operation is disabled.   
     
     
         16 . The data storage system according to  claim 15 , wherein
 the system interface command comprises one of a serial advanced technology attachment (SATA) set features command, a serial attached small computer system interface (SAS) mode select command, or a non-volatile memory express (NVMe) set features command.   
     
     
         17 . The data storage system according to  claim 11 , wherein
 the host is further configured to send an initiation command to the data storage device, the initiation command causing the control circuit to initiate the process for generating erased blocks in the non-volatile solid-state storage device in response to the initiation command, regardless of the set condition being met.   
     
     
         18 . The data storage system according to  claim 11 , wherein
 the condition includes at least a state that the number of erased blocks in the non-volatile solid-state storage device is less than a threshold value.   
     
     
         19 . The data storage system according to  claim 11 , wherein
 the data storage device is one of a plurality of data storage devices that form a data storage array coupled to the host.   
     
     
         20 . The data storage system according to  claim 11 , wherein
 the process for generating erased blocks in the non-volatile solid-state storage device comprises copying selectively valid data in first one or more erasable blocks of the non-volatile solid-state storage device to second one or more erasable blocks of the non-volatile solid-state storage device, and erasing data in the first one or more erasable blocks.