Support Questions
Find answers, ask questions, and share your expertise
Announcements
Alert: Welcome to the Unified Cloudera Community. Former HCC members be sure to read and learn how to activate your account here.

HDFS: Under-Replicated Blocks error in HDFS

Highlighted

HDFS: Under-Replicated Blocks error in HDFS

Explorer

Hi,

Can someone help me on the below issue, please?

19,124 under replicated blocks in the cluster. 38,288 total blocks in the cluster. Percentage under replicated blocks: 49.95%. Critical threshold: 40.00%.
and  Configured Capacity is  40.9 GiB/439.8 GiB
Please find the below report:  sudo -u hdfs hdfs dfsadmin -report

Configured Capacity: 472203141120 (439.77 GB)
Present Capacity: 461408686138 (429.72 GB)
DFS Remaining: 428312064000 (398.90 GB)
DFS Used: 33096622138 (30.82 GB)
DFS Used%: 7.17%
Replicated Blocks:
Under replicated blocks: 19124
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0
Low redundancy blocks with highest priority to recover: 19124
Pending deletion blocks: 0
Erasure Coded Block Groups:
Low redundancy block groups: 0
Block groups with corrupt internal blocks: 0
Missing block groups: 0
Low redundancy blocks with highest priority to recover: 0
Pending deletion blocks: 0

-------------------------------------------------
Live datanodes (1):

Name: 11.16.112.253:9866 (cdldtcoevap0001.es.ad.adp.com)
Hostname: cdldtcoevap0001.es.ad.adp.com
Rack: /default
Decommission Status : Normal
Configured Capacity: 472203141120 (439.77 GB)
DFS Used: 33096622138 (30.82 GB)
Non DFS Used: 10794454982 (10.05 GB)
DFS Remaining: 428312064000 (398.90 GB)
DFS Used%: 7.01%
DFS Remaining%: 90.71%
Configured Cache Capacity: 4294967296 (4 GB)
Cache Used: 0 (0 B)
Cache Remaining: 4294967296 (4 GB)
Cache Used%: 0.00%
Cache Remaining%: 100.00%
Xceivers: 2
Last contact: Fri Aug 02 09:08:32 EDT 2019
Last Block Report: Fri Aug 02 08:54:20 EDT 2019

 

Thanks,

Vijaya

1 REPLY 1

Re: HDFS: Under-Replicated Blocks error in HDFS

Cloudera Employee

Hi Vijaya,

 

Under-replicated blocks are the blocks which does not meet the target replication factor. HDFS has self healing mechanism wherein it will create new replicas of under-replicated blocks until they meet the target replication. 

if multi node cluster then you can verify if any datanodes are down  Or if it is one node cluster then please ensure replication factor is set to 1. 

 

Thanks.