error when starting up the mongodb cluster I have a cluser of mongodb of 3 nodes:
After increasing the max-openfile-count of the linux system user,
 I tried the following cluster startup commands after a rebooting the linux system without shutdowning mongodb cluster normally.

# log in each node:
1, /var/opt/mongodb-linux-x86_64-rhel62-3.4.5/bin/mongod -f /data/mongodbtest/config/mongo.conf
2, /var/opt/mongodb-linux-x86_64-rhel62-3.4.5/bin/mongod --maxConns=20000 -f /data/mongodbtest/shard1/mongo.conf --nojournal
3,-- /var/opt/mongodb-linux-x86_64-rhel62-3.4.5/bin/mongod --maxConns=20000 -f /data/mongodbtest/shard2/mongo.conf --nojournal
4,-- /var/opt/mongodb-linux-x86_64-rhel62-3.4.5/bin/mongod --maxConns=20000 -f /data/mongodbtest/shard3/mongo.conf --nojournal


when I run the step 2, the process stucked with following message:


I tried to delete the mongod.lock file in " /data/mongodbtest/shard1/data " and retry the process.
But the problem still exists.I don't know how can i fix this.
Without knowing what is content of /data/mongodbtest/shard1/mongo.conf, it's look like you don't have --fork (in config file processManagement.fork:true) set up. Parameter moves the process to background.

BTW, what is reason to --maxConns parameter?