Information processing device and system capable of preventing loss of user data

An information processing system comprising:

• a host device including a backup power source;
• and
• a plurality of storage devices connected to the host device, wherein
• the host device is configured to:
• supply power from the backup power source to each of the plurality of storage devices in response to a power loss,
• transmit a first instruction to each of the storage devices, upon the power loss, and
• transmit a second instruction to at least one of the storage devices, upon receiving a response to the first instruction from each of the storage devices, and wherein
• each of the storage devices comprises:
• a volatile memory;
• a non-volatile storage;
• and
• a controller configured to:
• manage mapping between logical addresses and physical addresses of the non-volatile storage using an address translation table,
• save, using power supplied from the backup power source of the host device, user data that are stored in the volatile memory and have not been written in the non-volatile storage in the non-volatile storage in response to the first instruction from the host device,
• transmit the response, which indicates completion of saving the user data, and
• save, using power supplied from the backup power source of the host device, updated address translation information that corresponds to the user data and has not been saved, in the non-volatile storage, in response to the second instruction from the host device.