[root@aabackup sgjdb]# du -sh * | grep 2019_03_18 
426M    aa2019_03_18_00_00_01.sql.gz.zip
427M    aa2019_03_18_03_00_01.sql.gz.zip
427M    aa2019_03_18_06_00_01.sql.gz.zip
428M    aa2019_03_18_09_00_01.sql.gz.zip
432M    aa2019_03_18_12_00_02.sql.gz.zip
434M    aa2019_03_18_15_00_01.sql.gz.zip
436M    aa2019_03_18_18_00_01.sql.gz.zip
438M    aa2019_03_18_21_00_01.sql.gz.zip
[root@aabackup sgjdb]# du -sh * | grep 2019_03_18 | awk '{val=gsub("M","",$1)}; {sum+=$val}; END {print sum/1024}'
3.36719
[root@aabackup sgjdb]# du -sh * | grep 2019_03_18 | awk '{val=gsub("M","",$1)}; {sum+=$val}; END {print sum/1024"G"}'
3.36719G