Zach Dwiel » fyi

mongorestore: ERROR: root directory must be a dump of a single collection when specifying a collection name with –collection

dwiel — Thu, 22 Apr 2010 02:20:38 +0000

mongorestore wants the specific collection's filename rather than the entire database's dump folder:


dwiel@dwiel$ mongodump -d db -c variables -o ../backups/1

connected to: 127.0.0.1

DATABASE: db	 to 	../backups/1/db

        db.variables to ../backups/1/db/variables.bson

                3 objects

dwiel@dwiel$ mongorestore -d db -c variables --drop ../backups/1

ERROR: root directory must be a dump of a single collection

       when specifying a collection name with --collection

usage: ........

dwiel@dwiel$ mongorestore -d db -c variables --drop ../backups/1/db/variables.bson

connected to: 127.0.0.1

../backups/1/db/variables.bson

        going into namespace [db.variables]

        dropping

        3 objects

quite obvious in retrospect given the error message, but the internet didn't know the answer yet and there isn't much documentation about mongorestore.

MySQL Permission Errors After Moving Datadir

dwiel — Thu, 12 Nov 2009 03:52:11 +0000

I wanted to make space on my root partition and so moved my mysql data dir to /home/mysql in /etc/mysql/my.conf and received the following errors:

dwiel@dwiel:~$ sudo mysqld 091111 20:39:16 [Warning] Can't create test file /home/mysql/dwiel.lower-test 091111 20:39:16 [Warning] Can't create test file /home/mysql/dwiel.lower-test 091111 20:39:16 [Note] Plugin 'FEDERATED' is disabled. mysqld: Can't find file: './mysql/plugin.frm' (errno: 13) 091111 20:39:16 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it. 091111 20:39:16 InnoDB: Operating system error number 13 in a file operation. InnoDB: The error means mysqld does not have the access rights to InnoDB: the directory. InnoDB: File name ./ibdata1 InnoDB: File operation call: 'open'. InnoDB: Cannot continue operation.

The problem was with apparmor. It was restricting mysql from reading and writing to /home/mysql. To correct this I edited the file /etc/apparmor.d/usr.sbin.mysqld and added:

/home/mysql r, /home/mysql** rwk,

to the end of the file. Then restarted apparmor:

sudo /etc/init.d/apparmor restart

and then restarted apache with no problem

Passwordless login for SSH not working

dwiel — Mon, 08 Dec 2008 07:22:12 +0000

I have not been able to login to my system with passwordless SSH for some time now and finally figured out the problem. I had to change the permissions of my home directory to disallow writing by everyone. I knew that ~/.ssh and the files in it required specific permissions to be set, but I hadn't heard about the home directory having similar requirements.