An information processing apparatus comprising: a plurality of processors each comprising a plurality of memories and a memory controller configured to control the plurality of memories; a normality checker configured to check whether the plurality of processors operate normally when the information processing apparatus is started; a failure detector configured to find any failed processor on the basis of a result of the checking by the normality checker; an isolation unit configured to isolate a failed processor and the plurality of memories of the failed processor if any; a redundancy determiner configured to determine, when the failed processor is isolated, whether the plurality of memories of one or more other processors are used in a redundancy configuration that makes the plurality of memories redundant; a redundancy cancellation determiner configured to determine, when the redundancy determiner determines that the plurality of memories of the other processors are used in the redundant configuration, whether the redundancy configuration of the plurality of memories of the other processors is to be cancelled to adjust an available memory size; a redundancy canceller configured to cancel, when the redundancy cancellation determiner determines that the redundancy configuration of the plurality of memories of the other processors is to be cancelled, the redundancy configuration of the plurality of memories of at least one of the other processors operating normally among the plurality of processors; a size adjusting determiner configured to determine, whether a memory size is to be adjusted; a memory size calculator configured to calculate, when the size adjusting determiner determines that the memory size is to be adjusted, an actual memory size available in the redundancy configuration before the failed processor is isolated and an available memory size available after the failed processor is isolated; and an adjustor configured to adjust an expected available memory size available after the isolation of the failed processor such that the expected available memory size approximates to the actual memory size available in the redundancy configuration before the isolation of the failed processor, characterized in that the size adjusting determiner determines whether a memory size is to be adjusted on the basis of size adjusting information that specifies the memory size is to be adjusted. a plurality of processors each comprising a plurality of memories and a memory controller configured to control the plurality of memories; a normality checker configured to check whether the plurality of processors operate normally when the information processing apparatus is started; a failure detector configured to find any failed processor on the basis of a result of the checking by the normality checker; an isolation unit configured to isolate a failed processor and the plurality of memories of the failed processor if any; a redundancy determiner configured to determine, when the failed processor is isolated, whether the plurality of memories of one or more other processors are used in a redundancy configuration that makes the plurality of memories redundant; a redundancy cancellation determiner configured to determine, when the redundancy determiner determines that the plurality of memories of the other processors are used in the redundant configuration, whether the redundancy configuration of the plurality of memories of the other processors is to be cancelled to adjust an available memory size; a redundancy canceller configured to cancel, when the redundancy cancellation determiner determines that the redundancy configuration of the plurality of memories of the other processors is to be cancelled, the redundancy configuration of the plurality of memories of at least one of the other processors operating normally among the plurality of processors; a size adjusting determiner configured to determine, whether a memory size is to be adjusted; a memory size calculator configured to calculate, when the size adjusting determiner determines that the memory size is to be adjusted, an actual memory size available in the redundancy configuration before the failed processor is isolated and an available memory size available after the failed processor is isolated; and an adjustor configured to adjust an expected available memory size available after the isolation of the failed processor such that the expected available memory size approximates to the actual memory size available in the redundancy configuration before the isolation of the failed processor,