fsck使用详解

• 文件系统检查 可指定目录

hadoop fsck /

找到相关块所属的文件

hadoop fsck -blockId blk_1073744391

• 找到文件中包含的块儿

hadoop fsck /user/file  -files -blocks -racks

• 输出信息明细

....................................................................................................
...................Status: HEALTHY
 Total size:    147035537415 B (Total open files size: 360 B)
 Total dirs:    1720
 Total files:   3719
 Total symlinks:        0 (Files currently being written: 5)
 Total blocks (validated):  3876 (avg. block size 37934865 B) (Total open file blocks (not validated): 4)
 Minimally replicated blocks:   3876 (100.0 %)
 Over-replicated blocks:    0 (0.0 %)
 Under-replicated blocks:   15 (0.3869969 %)
 Mis-replicated blocks:     0 (0.0 %)
 Default replication factor:    3
 Average block replication: 2.9669762
 Corrupt blocks:        0
 Missing replicas:      105 (0.9047824 %)
 Number of data-nodes:      3
 Number of racks:       1
FSCK ended at Wed Aug 19 18:09:03 CST 2020 in 102 milliseconds

status：代表这次hdfs上block检测的结果
Total size: 代表/目录下文件总大小
Total dirs：代表检测的目录下总共有多少个目录
Total files：代表检测的目录下总共有多少文件
Total symlinks：代表检测的目录下有多少个符号连接
Total blocks(validated)：代表检测的目录下有多少个block块是有效的
Minimally replicated blocks：代表拷贝的最小block块数
Over-replicated blocks：指的是副本数大于指定副本数的block数量
Under-replicated blocks：指的是副本数小于指定副本数的block数量
Mis-replicated blocks：指丢失的block块数量
Default replication factor: 3 指默认的副本数是3份（自身一份，需要拷贝两份）
Missing replicas：丢失的副本数
Number of data-nodes：有多少个节点
Number of racks：有多少个机架
Corrupt blocks : 坏块儿数

解决 针对无副本和坏块，解决办法
通过
hadoop fsck -move
hadoop fsck -delete 删除受影响的文件