檢視叢集基本情況(重要)!! 檢視hadoop叢集有多少節點(hdfs fsck /)
[email protected]:~$ hdfs fsck /
Connecting to namenode via http://localhost:9870/fsck?ugi=liugen&path=%2F
FSCK started by liugen (auth:SIMPLE) from /127.0.0.1 for path / at Wed Oct 24 20:39:11 PDT 2018
Status: HEALTHY //叢集狀態健康
Number of data-nodes: 1 //叢集有多少資料節點
Number of racks: 1 //叢集有多少機架
Total dirs: 7 //叢集有多少個目錄
Total symlinks: 0 //叢集有多少連結
Replicated Blocks:
Total size: 54396813 B //叢集總共檔案大小
Total files: 3 //叢集有多少個檔案
Total blocks (validated): 2 (avg. block size 27198406 B) //多少個數據塊 通過驗證的有2塊 平均塊大小是27xxx
Minimally replicated blocks: 2 (100.0 %) //最少複製的塊數
Over-replicated blocks: 0 (0.0 %) //超過預計複製數目的塊有幾個(比如說 多備份了1個副本)
Under-replicated blocks: 0 (0.0 %) // 少於預計複製數目的塊有幾個(比如說 3副本少備份了1個副本)
Mis-replicated blocks: 0 (0.0 %) //沒備份的塊有幾個
Default replication factor: 1 //備份因子為1 每個資料塊給1個備份
Average block replication: 1.0 //平均備份數目,1個備份
Missing blocks: 0
Corrupt blocks: 0
Missing replicas: 0 (0.0 %)
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
FSCK ended at Wed Oct 24 20:39:11 PDT 2018 in 20 milliseconds
The filesystem under path '/' is HEALTHY