I have a MongoDB 2.0.4 installation on Ubuntu 12.10. Recently I had some problems connecting to the database from the outside, and figured out there was something which prevented MongoDB from starting correctly. As suggested on several sources (see StackOverflow) I removed /var/lib/mongodb/mongodb.lock
and ran mongod --repair
. This didn't solve the problem, MongoDB wouldn't run and kept creating lock files that it didn't take care of removing afterwards. By looking at the logs, I realized that it didn't have access to some folder called $tmpSomething
, so (since the name suggested a temporary folder) I removed it, and afterwards it all worked … except the fact that I only have one of my previous databases in sight, while the other ones are still there because my /var/lib/mongodb/
folder is still full of .ns .0 .1 .n
files that weight a lot. Is there a way to restore them into the database? (I have tried with mongorestore, but as I was expecting, it doesn't handle those files).
Thanks
Best Answer
The
.ns .0 .1
etc. files are the data files themselves. If you started amongod
instance with a--dbpath
argument pointing at that folder, or if you moved the contents somewhere else and used the option to point there, mongod will attempt to read them as normal.Since your issues suggest corruption and/or some other issue starting
mongod
(you should really post the startup messages log files, perhaps in a separate question to address that issue), then there are alternatives. For reference, the most common problems are permissions related, especially when people try to start mongod manually (as themselves) or with sudo (as root) and create problematic permissions in the various directories.You are correct that
mongorestore
cannot use these data files directly, butmongodump
can read them and dump data from them into the BSON files thatmongorestore
expects.The option you want here is dbpath. You mention your path is
/var/lib/mongo
, so you can run something like this:Optionally you can use
--repair
here too to fix corruption along with the query options in extreme circumstances to get around corrupted sections (rarely, if ever, needed). The various options are described on themongodump
page:http://docs.mongodb.org/manual/reference/mongodump/
Once you dump the files out, you can use
mongorestore
to reimport them into anothermongod
instance.