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how to know the reason for missing blocks

we have ambari cluster with 3 masters machine and 4 datanode machine

we run the hdfs dfsadmin -report

and we found Missing blocks: 4

how to know the reason for these missing blocks?

second what is the workaround that we need to do regarding that?

hdfs dfsadmin -report
Configured Capacity: 8226130288640 (7.48 TB)
Present Capacity: 8225526102776 (7.48 TB)
DFS Remaining: 8205621209848 (7.46 TB)
DFS Used: 19904892928 (18.54 GB)
DFS Used%: 0.24%
Under replicated blocks: 4
Blocks with corrupt replicas: 0
Missing blocks: 4
Missing blocks (with replication factor 1): 0
-------------------------------------------------
Live datanodes (4):
Name: 10.164.252.32:50010 (worker03.sys76.com)
Hostname: worker03.sys76.com
Decommission Status : Normal
Configured Capacity: 1170504683520 (1.06 TB)
DFS Used: 5715611648 (5.32 GB)
Non DFS Used: 0 (0 B)
DFS Remaining: 1164727208338 (1.06 TB)
DFS Used%: 0.49%
DFS Remaining%: 99.51%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 6
Last contact: Wed Jan 31 13:34:02 UTC 2018
Name: 10.164.252.33:50010 (worker04.sys76.com)
Hostname: worker04.sys76.com
Decommission Status : Normal
Configured Capacity: 2351875026944 (2.14 TB)
DFS Used: 4573270016 (4.26 GB)
Non DFS Used: 0 (0 B)
DFS Remaining: 2347124950656 (2.13 TB)
DFS Used%: 0.19%
DFS Remaining%: 99.80%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 6
Last contact: Wed Jan 31 13:34:02 UTC 2018
Name: 10.164.252.31:50010 (worker02.sys76.com)
Hostname: worker02.sys76.com
Decommission Status : Normal
Configured Capacity: 2351875026944 (2.14 TB)
DFS Used: 5077798912 (4.73 GB)
Non DFS Used: 0 (0 B)
DFS Remaining: 2346627408110 (2.13 TB)
DFS Used%: 0.22%
DFS Remaining%: 99.78%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 6
Last contact: Wed Jan 31 13:34:02 UTC 2018
Name: 10.164.252.30:50010 (worker01.sys76.com)
Hostname: worker01.sys76.com
Decommission Status : Normal
Configured Capacity: 2351875551232 (2.14 TB)
DFS Used: 4538212352 (4.23 GB)
Non DFS Used: 0 (0 B)
DFS Remaining: 2347141642744 (2.13 TB)
DFS Used%: 0.19%
DFS Remaining%: 99.80%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 8
Last contact: Wed Jan 31 13:34:02 UTC 2018
Michael-Bronson
1 ACCEPTED SOLUTION

Accepted Solutions

Re: how to know the reason for missing blocks

Guru

@Michael Bronson , Missing data block can be related to data corruption. Use 'hdfs fsck <path> -list-corruptfileblocks -files -locations' to find out which replicas got corrupted.

Secondly, In order to fix issue, you can delete the corrupted blocks using 'hdfs fsck / -delete'

I hope you find below thread useful for handing missing blocks.

https://community.hortonworks.com/questions/17917/best-way-of-handling-corrupt-or-missing-blocks.htm...

View solution in original post

1 REPLY 1

Re: how to know the reason for missing blocks

Guru

@Michael Bronson , Missing data block can be related to data corruption. Use 'hdfs fsck <path> -list-corruptfileblocks -files -locations' to find out which replicas got corrupted.

Secondly, In order to fix issue, you can delete the corrupted blocks using 'hdfs fsck / -delete'

I hope you find below thread useful for handing missing blocks.

https://community.hortonworks.com/questions/17917/best-way-of-handling-corrupt-or-missing-blocks.htm...

View solution in original post