1. On Redhat 6.2 after uninstalling a cluster, and re-install IDH 2.5.1, you meet a "can not write /etc/nginx/nginx.conf" and you can not install IDH

root cause: when you uninstall, there is an error "cannot connect to the IDH or OS yum reposity." and the uninstallation is not fully completed

solution:

1.1.you remove the repo list /ect/yum.repos.d/ that are not os and idh and run yum clean all

1.2. when you install IDH again, you check /etc/nginx folder and check if it exists. if not, run yum install nginx or go to intelhadoop/idh/hadoop_related/common/puppet

and run rpm -i nginx...

2. when IM in the formatting period, standy NN Tab goes into error without any error info and the DRBD syn seems not started.

2.1. check /var/log/intelmanager/ and find the SNN install log and find that there are errors deleting /mnt/diskX/data/subdirNN.

2.2. delete the obsolete data dir.

2.3. formatting cluster again.