Systems, methods, and devices for fault resilient storage

Abstract

A method of operating a storage device may include determining a fault condition of the storage device, selecting a fault resilient mode based on the fault condition of the storage device, and operating the storage device in the selected fault resilient mode. The selected fault resilient mode may include one of a power cycle mode, a reformat mode, a reduced capacity read-only mode, a reduced capacity mode, a reduced performance mode, a read-only mode, a partial read-only mode, a temporary read-only mode, a temporary partial read-only mode, or a vulnerable mode. The storage device may be configured to perform a namespace capacity management command received from the host. The namespace capacity management command may include a resize subcommand and/or a zero-size namespace subcommand. The storage device may report the selected fault resilient mode to a host.

1 . A method of operating a storage array, the method comprising:
 determining a first fault resilient operating mode of a first fault resilient storage device of the storage array;   determining a second fault resilient operating mode of a second fault resilient storage device of the storage array;   allocating one or more rescue spaces of one or more additional fault resilient storage devices of the storage array;   mapping user data from the first fault resilient storage device to the one or more rescue spaces; and   mapping user data from the second fault resilient storage device to the one or more rescue spaces.   
     
     
         2 . The method of  claim 1 , further comprising reassigning at least one device identifier (ID) of the one or more additional fault resilient storage devices to a device ID of the first fault resilient storage device. 
     
     
         3 . The method of  claim 2 , wherein the at least one device ID of the one or more additional fault resilient storage devices is reassigned based on a current unaffected device ID and a current faulty device ID. 
     
     
         4 . The method of  claim 1 , further comprising redirecting one or more inputs and/or outputs (ID) from the first fault resilient storage device to the one or more additional fault resilient storage devices. 
     
     
         5 . The method of  claim 1 , wherein the user data comprises a strip of data. 
     
     
         6 . The method of  claim 5 , wherein the strip of data is redirected to a target storage device of the one or more additional fault resilient storage devices based on a stripe ID of the user data. 
     
     
         7 . The method of  claim 1 , wherein mapping user data from the first fault resilient storage device to the one or more rescue spaces comprises maintaining a first mapping table. 
     
     
         8 . The method of  claim 7 , wherein mapping user data from the second fault resilient storage device to the one or more rescue spaces comprises maintaining a second mapping table. 
     
     
         9 . The method of  claim 1 , wherein the one or more rescue spaces have a rescue space percentage ratio of a storage device capacity. 
     
     
         10 . The method of  claim 9 , wherein the rescue space percentage ratio is greater than or equal to a number of failed storage devices accommodated by the storage array, divided by the total number of storage devices in the storage array. 
     
     
         11 . The method of  claim 1 , wherein the one or more rescue spaces are allocated statically. 
     
     
         12 . The method of  claim 1 , wherein the one or more rescue spaces are allocated dynamically. 
     
     
         13 . A system comprising a storage array comprising:
 a first fault resilient storage device;   a second fault resilient storage device;   one or more additional fault resilient storage devices; and   a volume manger configured to:
 determine a first fault resilient operating mode of the first fault resilient storage device; 
 determine a second fault resilient operating mode of the second fault resilient storage device; 
 allocate one or more rescue spaces of one or more additional fault resilient storage devices of the storage array; 
 map user data from the first fault resilient storage device to the one or more rescue spaces; and 
 map user data from the second fault resilient storage device to the one or more rescue spaces. 
   
     
     
         14 . The system of  claim 13 , wherein the volume manger is further configured to reassign at least one device identifier (ID) of the one or more additional fault resilient storage devices to a device ID of the first fault resilient storage device. 
     
     
         15 . The system of  claim 13 , wherein the volume manger is further configured to redirect one or more inputs and/or outputs (IOs) from the first fault resilient storage device to the one or more additional fault resilient storage devices. 
     
     
         16 . The system of  claim 13 , wherein:
 the user data comprises a strip of data; and   the volume manger is further configured to redirect the strip of data to a target storage device of the one or more additional fault resilient storage devices based on a stripe ID of the user data.   
     
     
         17 . The system of  claim 13 , wherein:
 the one or more rescue spaces have a rescue space percentage ratio of a storage device capacity; and   the rescue space percentage ratio is based on a number of failed storage devices accommodated by the storage array, divided by a total number of storage devices in the storage array.   
     
     
         18 . An apparatus comprising a volume manager for a storage array, the volume manager comprising logic configured to:
 determine a first fault resilient operating mode of a first fault resilient storage device of the storage array;   determine a second fault resilient operating mode of a second fault resilient storage device of the storage array;   allocate one or more rescue spaces of one or more additional fault resilient storage devices of the storage array;   map user data from the first fault resilient storage device to the one or more rescue spaces; and   map user data from the second fault resilient storage device to the one or more rescue spaces.   
     
     
         19 . The apparatus of  claim 18 , wherein:
 the user data comprises a strip of data; and   the strip of data is redirected to a target storage device of the one or more additional fault resilient storage devices based on a stripe identifier (ID) of the user data.   
     
     
         20 . The apparatus of  claim 18 , wherein:
 the one or more rescue spaces have a rescue space percentage ratio of a storage device capacity; and   the rescue space percentage ratio is based on a number of failed storage devices accommodated by the storage array, divided by a total number of storage devices in the storage array.