We are only runnng hdfs, so we only need to upgrade that. Since it was a dev environment, we shut all of hdfs down, download hadoop-2.6.0-cdh5.8.4.tar.gz from http://archive.cloudera.com/cdh5/cdh/5/ and run with that.   (We are actually running with hdfs on mesos, so the artifacts get packaged up into an uberjar with the mesos executor, but there's no real magic there.  I think it just uses the stuff in hadoop/common and hadoop/hdfs and some of the run scripts.) ... View more

Downgrading from 2.6.0-cdh5.9.1 back to 2.6.0-cdh5.8.4 looks to have fixed the problem. Our HDFS is back to being usable and stable.     ... View more

We have the same issue. We upgraded from 2.6.0 CDH 5.7.6 to 2.6.0 CDH 5.9.1. Since then, our data nodes have been leaking open file descriptors to block .meta files. We didn't have any issues before the upgrade. The screen shot attached shows the change in behavior after the upgrade for one of our data nodes. The drop downs occur when we restart the HDFS service.   ... View more