Salvaging event trace information in power loss interruption scenarios

The invention relates to a method and apparatus for salvaging event trace information in power loss interruption (PLI) scenarios in solid-state drive SSD 102 and hard disk drive (HDD) storage devices. If volatile state information that is salvaged after an inadvertent power loss were to include event trace information 202, then such information can provide a valuable debug resource. Event trace information from volatile memory is copied to a second memory upon a power on which is in response to a PLI event 202. A corrupt state of context reconstruction data stored on non-volatile memory is detected 204, and an indication of the corrupt state is set 206. The event trace information is then passed to the host if requested based on the indication 208. In response to a request from the host the trace information may be passed to the host for use with a fault tolerant debug tool comprising an interface engine configured for inferring a legitimate trace character from a malformed trace character. This may be based on the assumption that each bit representing an event trace information will decay form a 1 to a 0 as the first volatile memory is losing power due to the power loss interruption. The first volatile memory may be a DRAM, whilst the second memory may be a NAND flash memory or may be the same as the first memory. Embodiments comprise a solid state drive controller (112 figure 1) to store one or more sequence of instructions for executing the method, whilst another embodiment utilises a storage device comprising a communication interface (110, figure 1) for communicating with the host (104), non volatile media (120) and a controller (112).