1、配置方式
2、实际操作演示
（1）在Hadoop用户的根目录下创建text.txt文件
（2）上传文件
hadoop@node1:~$ hdfs dfs -ls hdfs://node1:8020/
Found 4 items
drwxr-xr-x - hadoop supergroup 0 2023-11-21 23:06 hdfs://node1:8020/home
-rw-r--r-- 2 hadoop supergroup 35 2023-11-26 22:54 hdfs://node1:8020/text.txt
-rw-r--r-- 3 hadoop supergroup 27 2023-11-26 22:57 hdfs://node1:8020/three_text.txt
drwx------ - hadoop supergroup 0 2023-11-18 12:21 hdfs://node1:8020/user
（3）修改副本数
hadoop@node1:~$ hdfs dfs -setrep 1 hdfs://node1:8020/three_text.txt
Replication 1 set: hdfs://node1:8020/three_text.txt
hadoop@node1:~$ hdfs dfs -ls hdfs://node1:8020/
Found 4 items
drwxr-xr-x - hadoop supergroup 0 2023-11-21 23:06 hdfs://node1:8020/home
-rw-r--r-- 2 hadoop supergroup 35 2023-11-26 22:54 hdfs://node1:8020/text.txt
-rw-r--r-- 1 hadoop supergroup 27 2023-11-26 22:57 hdfs://node1:8020/three_text.txt
drwx------ - hadoop supergroup 0 2023-11-18 12:21 hdfs://node1:8020/user
3、fsck命令检查文件的副本数
（1）结果演示：
hadoop@node1:~$ hdfs fsck hdfs://node1:8020/text.txt -files -blocks -locations
Connecting to namenode via http://node1:9870/fsck?ugi=hadoop&files=1&blocks=1&locations=1&path=%2Ftext.txt
FSCK started by hadoop (auth:SIMPLE) from /192.168.88.101 for path /text.txt at Sun Nov 26 23:07:44 CST 2023
/text.txt 35 bytes, replicated: replication=2, 1 block(s): OK
0. BP-1383297113-192.168.88.101-1699274849934:blk_1073741835_1012 len=35 Live_repl=2 [DatanodeInfoWithStorage[192.168.88.103:9866,DS-89bf9985-fca9-4717-bdd1-1476f0b98a0f,DISK], DatanodeInfoWithStorage[192.168.88.101:9866,DS-bc41ebe7-7da0-4097-813b-7a025fba1b99,DISK]]
Status: HEALTHY
Number of data-nodes: 3
Number of racks: 1
Total dirs: 0
Total symlinks: 0
Replicated Blocks:
Total size: 35 B
Total files: 1
Total blocks (validated): 1 (avg. block size 35 B)
Minimally replicated blocks: 1 (100.0 %)
Over-replicated blocks: 0 (0.0 %)
Under-replicated blocks: 0 (0.0 %)
Mis-replicated blocks: 0 (0.0 %)
Default replication factor: 3
Average block replication: 2.0
Missing blocks: 0
Corrupt blocks: 0
Missing replicas: 0 (0.0 %)
Blocks queued for replication: 0
Erasure Coded Block Groups:
Total size: 0 B
Total files: 0
Total block groups (validated): 0
Minimally erasure-coded block groups: 0
Over-erasure-coded block groups: 0
Under-erasure-coded block groups: 0
Unsatisfactory placement block groups: 0
Average block group size: 0.0
Missing block groups: 0
Corrupt block groups: 0
Missing internal blocks: 0
Blocks queued for replication: 0
FSCK ended at Sun Nov 26 23:07:44 CST 2023 in 1 milliseconds
The filesystem under path '/text.txt' is HEALTHY
（2）分析
