FOSS gamedev and creative worlds

Have been running a server on our home network for my kids, they are accessing the server with a linux mint machine, a windows xp machine and an android tablet as well.
Logged into server today and had the following fault. Random blocks have appeared all over the world overwriting placed blocks and filling excavated spaces and buildings including overwriting things like locked chests. Here's the info in the debug.txt

14:12:09: ACTION[main]: .__ __ __
14:12:09: ACTION[main]: _____ |__| ____ _____/ |_ ____ _______/ |_
14:12:09: ACTION[main]: / \| |/ \_/ __ \ __\/ __ \ / ___/\ __\
14:12:09: ACTION[main]: | Y Y \ | | \ ___/| | \ ___/ \___ \ | |
14:12:09: ACTION[main]: |__|_| /__|___| /\___ >__| \___ >____ > |__|
14:12:09: ACTION[main]: \/ \/ \/ \/ \/
14:12:09: ACTION[main]: World at [/home/andy/.minetest/worlds/Dyeville]
14:12:09: ACTION[main]: Server for gameid="minetest" listening on port 30011.
creative inventory size: 203
14:12:10: ACTION[ServerThread]: singleplayer joins game. List of players: singleplayer
Font size: 8 15
14:13:33: ACTION[ServerThread]: Nat joins game. List of players: Nat
node_dig
14:14:21: ACTION[ServerThread]: Nat digs default:dirt at (-2,3,-9)
14:14:36: ERROR[ServerThread]: WARNING: Block failed to save (-3, -2, 2) database is locked
node_dig
14:14:45: ACTION[ServerThread]: Nat digs default:cobble at (-2,3,-8)
node_dig
14:14:50: ACTION[ServerThread]: Nat digs default:dirt at (-2,4,-9)
node_dig
14:14:51: ACTION[ServerThread]: Nat digs default:dirt at (-2,5,-9)
node_dig
14:14:53: ACTION[ServerThread]: Nat digs default:dirt at (-2,4,-8)
node_dig
14:14:54: ACTION[ServerThread]: Nat digs default:dirt at (-2,5,-8)
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-4, 0, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-4, 1, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-3, 0, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-3, 1, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-3, 1, 2) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-2, 1, -1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-1, 0, -1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-1, 0, 0) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-1, 1, 0) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-1, 0, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (-1, 1, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (0, 0, -1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (0, 0, 0) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (0, 0, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (0, 1, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (1, 1, -3) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (1, 0, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (2, -1, 1) database is locked
14:14:55: ERROR[ServerThread]: WARNING: Block failed to save (3, -1, 1) database is locked

The above warning has then appeared probably a couple of hundred times.
Is there a way to easily roll back the database to go back to the point before it all went wrong, it would be ok to loose recent activity as long as we can have the world we had this morning and no I didn't have the database backed up (which files do I need to backup?).

Thanks
Andy

Minetest version 0.4.7
Linux Mint v16

You unfortanely cannot rollback the world.
To backup the map just create a .zip or .tar.gz from the map folder (/home/andy/.minetest/worlds/Dyeville in your case) and store it somewhere.

Thanks for the info, maybe we'll start fresh with some different mods and things like jungle and dungeons enabled. I'll also set up a daily backup of the world folder.

andyd wrote:Minetest version 0.4.7
Linux Mint v16

Minetest homepage wrote:Minetest 0.4.10

1) Update
2) Test again

I am unable to install the 0.4.10 version as it fails every time on "post install triggers man-db", I've tried reinstalling the man-db package but minecraft 0.4.10 install still fails.
Any ideas?

andyd wrote:I am unable to install the 0.4.10 version as it fails every time on "post install triggers man-db", I've tried reinstalling the man-db package but minecraft 0.4.10 install still fails.
Any ideas?

Report this bug to the Debian maintainer for the minetest package.

andyd wrote:I've tried reinstalling the man-db package but minecraft 0.4.10 install still fails.
Any ideas?

I've an idea but that's possibly self-explaining.

EDIT: Seems like sfan5 also pointed to this. There are other players which got it working.