How do I unlock a SQLite database?

Question

sqlite> DELETE FROM mails WHERE (`id` = 71);
SQL error: database is locked

How do I unlock the database so this will work?

Answer 1

I got this error in a scenario a little different from the ones describe here.

The SQLite database rested on a NFS filesystem shared by 3 servers. On 2 of the servers I was able do run queries on the database successfully, on the third one thought I was getting the "database is locked" message.

The thing with this 3rd machine was that it had no space left on /var. Everytime I tried to run a query in ANY SQLite database located in this filesystem I got the "database is locked" message and also this error over the logs:

Aug 8 10:33:38 server01 kernel: lockd: cannot monitor 172.22.84.87

And this one also:

Aug 8 10:33:38 server01 rpc.statd[7430]: Failed to insert: writing /var/lib/nfs/statd/sm/other.server.name.com: No space left on device Aug 8 10:33:38 server01 rpc.statd[7430]: STAT_FAIL to server01 for SM_MON of 172.22.84.87

After the space situation was handled everything got back to normal.