hadoop-hdfs-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Chathuri Wimalasena <kamalas...@gmail.com>
Subject Safe mode on after restarting hadoop
Date Thu, 22 Dec 2016 16:02:49 GMT

We have a hadoop cluster with 10 data nodes. We had a disk failure with the
login node where the namenode, secondary namenode running and replaced the
failed disk. Failed disk does not affect the data, it only affected the
operating system. After replacing the failed disk, when I restart the
hadoop services, hadoop is set to safe mode and does not let run jobs.
Below message shows in namenode UI.

Safe mode is ON. The reported blocks 391253 needs additional 412776 blocks
to reach the threshold 0.9990 of total blocks 804833. The number of live
datanodes 10 has reached the minimum number 0. Safe mode will be turned off
automatically once the thresholds have been reached.

I can see all the data nodes are up and running. Also when I check for
corrupt blocks, it shows as 0.

hdfs fsck / -list-corruptfileblocks
Connecting to namenode via
The filesystem under path '/' has 0 CORRUPT files

Any idea what's going on ? I can forcefully leave the safemode, but I'm
worried whether it might cause data corruption. Are there any safety steps
I should do before leave the safemode forcefully ?


View raw message