'mongod wiredTiger' on Ubuntu?

Question

I cannot use wiredTiger as a service for MongoDB.

I followed this step by step guide;
http://docs.mongodb.org/manual/release-notes/3.0-upgrade/

Step-1: Start 3.0 mongod.OK, I did.
Step-2: Export the data using mongodump. OK
Step-3: Create data directory for WiredTiger. OK - user permissions were adjusted.
Step-4: Restart the mongod with WiredTiger. OK

mongod --storageEngine wiredTiger --dbpath <newWiredTigerDBPath>
And yes, mongod worked. But the Step-5 says that "Upload the exported data using mongorestore." However my console remains busy and says "waiting for connections on port 27017" because the last command does not include a service like service mongod start.

Then I tried editing my /etc/mongod.conf file to run as a service. But I couldn't. I added wiredTiger directory as dbpath but I guess I need to edit /etc/init/mongod.conf file because it contains some codes that change the permissions of the db directory.

After spending 8 hours, I don't think there's sufficient documentation to help, so I'd like to ask;
What should I do in order to be able to use wiredTiger with MongoDB?
I'm wondering if there's anybody who has managed to achieve this?

console

Edit on 2015-04-01: I tried change-storage-engine-to-wiredtiger section that is on the documentation.

Answer 1

I wasn't able to use wiredTiger upgrading MongoDB. However, at May 17 I uninstalled MongoDB 2.6 then installed MongoDB 3.0.3 . Immediate after the installation, I added storageEngine=wiredTiger on top of my mongod.conf file. Then I gave sudo service mongod start command and eventually I could.

---

Edit:

For fresh installed as directed by official documentation;

1. Open configuration file using sudo nano /etc/mongod.conf
2. Change the # engine line to engine: wiredTiger like the below
3. Run mongod using the command sudo service mongod start

.

# Where and how to store data.
storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true
  engine: wiredTiger
#  mmapv1:
#  wiredTiger:

---

Edit:

If the current version is supported the wiredTiger;

1. Get the backup of the current database using mongodump command
2. Stop the mongod service using sudo service mongod stop command
3. Add storageEngine=wiredTiger text as the first line of mongod.conf file
4. Delete the all file on /var/lib/mongodb (or /data/db folder if used)
   [This is important. Because MongoDB cannot convert the current MMAP db files to wiredTiger format]
5. Start the mongod service using sudo service mongod start command
6. Restore the database from the backup using [mongorestore][2] command
7. wiredTiger is being used...

Answer 2

Steps for migrating 2.6 to 3.0 on Ubuntu and using the new WiredTiger storage engine:

1. Backup current database:

   mongodump --out final_2.6_backup

2. Stop mongodb service:

   service mongodb stop

3. Remove current database files:

   rm -rf /var/lib/mongodb/*

4. Edit /etc/mongod.conf to use the new storage engine:

   storageEngine=wiredTiger

5. Start mongodb:

   service mongodb start

6. Restore database:

   mongorestore final_2.6_backup

Answer 3

I use wiredTiger in a sharded cluster. I find it easier to roll a hidden node into each replica set and then swap the 4th node with a secondary.

I then: 1. stop the MongoDB service on the now 4th node 2. restart the instance, as a service, pointed to the new dbpath for and the storageengine option set to wiredTiger. 3. wait for the node to synch. 4. drop the old dbpath

I repeat that step until all nodes are up to date.

• If you are not using a replica set, it does appear you are limited to using mongodump and mongorestore. We have way too much data to rely on those tools. They take too long to execute.