the m2 read cache in a synology filer is "critical" but still appears to be functioning

20230309172716-debut-nvme-smart

emory@debut:/volume1/docker$ sudo nvme smart-log /dev/nvme0
Smart Log for NVME device:nvme0 namespace-id:ffffffff
critical_warning                    : 0x4
temperature                         : 18 C
available_spare                     : 100%
available_spare_threshold           : 10%
percentage_used                     : 104%
data_units_read                     : 1,097,736,246
data_units_written                  : 526,487,556
host_read_commands                  : 32,712,112,528
host_write_commands                 : 4,110,610,595
controller_busy_time                : 311,598
power_cycles                        : 13
power_on_hours                      : 44,770
unsafe_shutdowns                    : 7
media_errors                        : 0
num_err_log_entries                 : 84
Warning Temperature Time            : 0
Critical Composite Temperature Time : 0
Temperature Sensor 1                : 0 C
Temperature Sensor 2                : 0 C
Temperature Sensor 3                : 0 C
Temperature Sensor 4                : 0 C
Temperature Sensor 5                : 0 C
Temperature Sensor 6                : 0 C
Temperature Sensor 7                : 0 C
Temperature Sensor 8                : 0 C