Couldn't connect to server 127.0.0.1:27017

I'm getting the following error:

alex@alex-K43U:/$ mongo
MongoDB shell version: 2.2.0
connecting to: test
Thu Oct 11 11:46:53 Error: couldn't connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91
exception: connect failed
alex@alex-K43U:/$ 

This is what happens when I try to start mongodb:

* Starting database mongodb                                             [fail]

I already tried mongo --repair

I made chown and chmod to var, lib, and data/db and log mongodb.

Not sure what else to do. Any suggestions?

mongodb.log:

***** SERVER RESTARTED *****


Thu Oct 11 08:29:40 
Thu Oct 11 08:29:40 warning: 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.
Thu Oct 11 08:29:40 
Thu Oct 11 08:29:41 [initandlisten] MongoDB starting : pid=1052 port=27017 dbpath=/var/lib/mongodb 32-bit host=alex-K43U
Thu Oct 11 08:29:41 [initandlisten] 
Thu Oct 11 08:29:41 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are limited to about 2 gigabytes of data
Thu Oct 11 08:29:41 [initandlisten] **       see http://blog.mongodb.org/post/137788967/32-bit-limitations
Thu Oct 11 08:29:41 [initandlisten] **       with --journal, the limit is lower
Thu Oct 11 08:29:41 [initandlisten] 
Thu Oct 11 08:29:41 [initandlisten] db version v2.2.0, pdfile version 4.5
Thu Oct 11 08:29:41 [initandlisten] git version: f5e83eae9cfbec7fb7a071321928f00d1b0c5207
Thu Oct 11 08:29:41 [initandlisten] build info: Linux domU-12-31-39-01-70-B4 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_49
Thu Oct 11 08:29:41 [initandlisten] options: { config: "/etc/mongodb.conf", dbpath: "/var/lib/mongodb", logappend: "true", logpath: "/var/log/mongodb/mongodb.log" }
Thu Oct 11 08:29:41 [initandlisten] Unable to check for journal files due to: boost::filesystem::basic_directory_iterator constructor: No such file or directory: "/var/lib/mongodb/journal"
************** 
Unclean shutdown detected.
Please visit http://dochub.mongodb.org/core/repair for recovery instructions.
*************
Thu Oct 11 08:29:41 [initandlisten] exception in initAndListen: 12596 old lock file, terminating
Thu Oct 11 08:29:41 dbexit: 
Thu Oct 11 08:29:41 [initandlisten] shutdown: going to close listening sockets...
Thu Oct 11 08:29:41 [initandlisten] shutdown: going to flush diaglog...
Thu Oct 11 08:29:41 [initandlisten] shutdown: going to close sockets...
Thu Oct 11 08:29:41 [initandlisten] shutdown: waiting for fs preallocator...
Thu Oct 11 08:29:41 [initandlisten] shutdown: closing all files...
Thu Oct 11 08:29:41 [initandlisten] closeAllFiles() finished
Thu Oct 11 08:29:41 dbexit: really exiting now

EDIT:

I removed the lock then did mongod repair and got this error:

Thu Oct 11 12:05:37 [initandlisten] exception in initAndListen: 10309 Unable to create/open lock file: /data/db/mongod.lock errno:13 Permission denied Is a mongod instance already running?, terminating

so I did it with sudo:

alex@alex-K43U:~$ sudo mongod --repair
Thu Oct 11 12:05:42 
Thu Oct 11 12:05:42 warning: 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.
Thu Oct 11 12:05:42 
Thu Oct 11 12:05:42 [initandlisten] MongoDB starting : pid=5129 port=27017 dbpath=/data/db/ 32-bit host=alex-K43U
Thu Oct 11 12:05:42 [initandlisten] 
Thu Oct 11 12:05:42 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are limited to about 2 gigabytes of data
Thu Oct 11 12:05:42 [initandlisten] **       see http://blog.mongodb.org/post/137788967/32-bit-limitations
Thu Oct 11 12:05:42 [initandlisten] **       with --journal, the limit is lower
Thu Oct 11 12:05:42 [initandlisten] 
Thu Oct 11 12:05:42 [initandlisten] db version v2.2.0, pdfile version 4.5
Thu Oct 11 12:05:42 [initandlisten] git version: f5e83eae9cfbec7fb7a071321928f00d1b0c5207
Thu Oct 11 12:05:42 [initandlisten] build info: Linux domU-12-31-39-01-70-B4 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_49
Thu Oct 11 12:05:42 [initandlisten] options: { repair: true }
Thu Oct 11 12:05:42 [initandlisten] Unable to check for journal files due to: boost::filesystem::basic_directory_iterator constructor: No such file or directory: "/data/db/journal"
Thu Oct 11 12:05:42 [initandlisten] finished checking dbs
Thu Oct 11 12:05:42 dbexit: 
Thu Oct 11 12:05:42 [initandlisten] shutdown: going to close listening sockets...
Thu Oct 11 12:05:42 [initandlisten] shutdown: going to flush diaglog...
Thu Oct 11 12:05:42 [initandlisten] shutdown: going to close sockets...
Thu Oct 11 12:05:42 [initandlisten] shutdown: waiting for fs preallocator...
Thu Oct 11 12:05:42 [initandlisten] shutdown: closing all files...
Thu Oct 11 12:05:42 [initandlisten] closeAllFiles() finished
Thu Oct 11 12:05:42 [initandlisten] shutdown: removing fs lock...
Thu Oct 11 12:05:42 dbexit: really exiting now

But still having the same problem.

Solution 1:

Step 1: Remove lock file.
sudo rm /var/lib/mongodb/mongod.lock

Step 2: Repair mongodb. 
sudo mongod --repair 

Step 3: start mongodb.
sudo start mongodb 
or
sudo service mongodb start

Step 4: Check status of mongodb.
sudo status mongodb 
or   
sudo service mongodb status

Step 5: Start mongo console.
mongo 

Solution 2:

Did you run mongod before running mongo?

I followed installation instructions for mongodb from http://docs.mongodb.org/manual/tutorial/install-mongodb-on-os-x/ and I had the same error as you only when I ran mongo before actually running the mongo process with mongod. I thought installing mongodb would also launch it but you need to launch it manually with mongod before you do anything else that needs mongodb.

Solution 3:

This it's because the mongod process it's down, you must to run the commands bellow in order to get up the mongod process:

~$ sudo service mongodb stop

~$ sudo rm /var/lib/mongodb/mongod.lock

~$ sudo mongod --repair --dbpath /var/lib/mongodb

~$ sudo mongod --fork --logpath /var/lib/mongodb/mongodb.log --dbpath /var/lib/mongodb

~$ sudo service mongodb start

Hope this helps you.