How to create a minecraft server? - 1

And how do I copy a single player map and put it into the server?

Why does my minecraft server crash everytime I open it?

DVPs-iMac: csg DVP$ java -Xmx6144M -Xms6144M -jar minecraft_server.1.7.4.jar
[21:08:31] [Server thread/INFO]: Starting minecraft server version 1.7.4
[21:08:31] [Server thread/INFO]: Loading properties
[21:08:31] [Server thread/INFO]: Default game type: SURVIVAL
[21:08:31] [Server thread/INFO]: Generating keypair
[21:08:32] [Server thread/INFO]: Starting Minecraft server on *:25565
[21:08:32] [Server thread/INFO]: Preparing level "world"
[21:08:32] [Server thread/INFO]: Preparing start region for level 0
[21:08:33] [Server thread/INFO]: Preparing spawn area: 50%
[21:08:33] [Server thread/INFO]: Done (1.528s)! For help, type "help" or "?"
[21:09:36] [User Authenticator #1/INFO]: UUID of player griffin0505 is feff78fdf3d14fc999b881faf6270bc4
[21:09:36] [Server thread/INFO]: griffin0505[/25.19.22.166:59506] logged in with entity id 38 at (-352.1482965482415, 65.24918707874468, 49.822449774073824)
[21:09:36] [Server thread/INFO]: griffin0505 joined the game
[21:09:37] [Server thread/ERROR]: Encountered an unexpected exception
s: Exception ticking world
at net.minecraft.server.MinecraftServer.u(S… ~[minecraft_server.1.7.4.jar:?]
at lm.u(SourceFile:265) ~[minecraft_server.1.7.4.jar:?]
at net.minecraft.server.MinecraftServer.t(S… ~[minecraft_server.1.7.4.jar:?]
at net.minecraft.server.MinecraftServer.run… [minecraft_server.1.7.4.jar:?]
at lb.run(SourceFile:616) [minecraft_server.1.7.4.jar:?]
Caused by: java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Random.java:250… ~[?:1.6.0_51]
at agr.a(SourceFile:183) ~[minecraft_server.1.7.4.jar:?]
at agr.a(SourceFile:27) ~[minecraft_server.1.7.4.jar:?]
at agl.a(SourceFile:364) ~[minecraft_server.1.7.4.jar:?]
at apq.a(SourceFile:432) ~[minecraft_server.1.7.4.jar:?]
at ml.a(SourceFile:160) ~[minecraft_server.1.7.4.jar:?]
at aoo.a(SourceFile:772) ~[minecraft_server.1.7.4.jar:?]
at ml.c(SourceFile:95) ~[minecraft_server.1.7.4.jar:?]
at ml.d(SourceFile:108) ~[minecraft_server.1.7.4.jar:?]
at afs.e(SourceFile:311) ~[minecraft_server.1.7.4.jar:?]
at mm.g(SourceFile:234) ~[minecraft_server.1.7.4.jar:?]
at mm.b(SourceFile:137) ~[minecraft_server.1.7.4.jar:?]
at net.minecraft.server.MinecraftServer.u(S… ~[minecraft_server.1.7.4.jar:?]
… 4 more
[21:09:37] [Server thread/ERROR]: This crash report has been saved to: U

Added (1). here is another try as requested
18:51:28 WARN]: To start the server with more ram, launch it as "java -Xmx1024M -Xms1024M -jar minecraft_server.jar"
[18:51:28 INFO]: Loading properties
[18:51:28 INFO]: Default game type: SURVIVAL
[18:51:28 INFO]: Generating keypair
[18:51:28 INFO]: Starting Minecraft server on *:25565
[18:51:28 INFO]: Preparing level "world"
[18:51:28 INFO]: Preparing start region for level 0
[18:51:29 INFO]: Preparing spawn area: 56%
[18:51:30 INFO]: Done (1.518s)! For help, type "help" or "?"
[18:54:20 INFO]: UUID of player griffin0505 is feff78fdf3d14fc999b881faf6270bc4
[18:54:20 INFO]: griffin0505[/25.19.22.166:57807] logged in with entity id 37 at (-352.1482965482415, 65.24918707874468, 49.822449774073824)
[18:54:20 INFO]: griffin0505 joined the game
[18:54:20 ERROR]: Encountered an unexpected exception
s: Exception ticking world
at net.minecraft.server.MinecraftServer.u(S… ~[minecraft_server.1.7.4.jar:?]
at

How do minecraft servers work with modpacks?

I just recently got into Minecraft for the pc and I was wondering how servers works exactly (I don't know anything about servers).

If you install a modpack(Like Feed The Beast) on a server do you still need it on the computer youre playing on or does it just somehow magically work?

How to give the Server code for minecraft and rank them?

Okay I got a Server code:25565 but my friend can't connect to it, plus I also can't get the code to change it from survival mode to creative mode, and of course rank them to Co-Owner. Can anyone help me?

Oh before I forget I also got the 1.7.4 Minecraft server launcher also, the 1.5.2 game from the main site, and the 1.5.2 Minecraft server launcher from a different site.

Will Port Forwarding a Router mess up anything?

So, I've been trying to make a Minecraft Server for a while and I've now got a Router that works with port forwarding. I asked my Dad if I could port forward, but he says that I might screw it up. When I port forward a router, will anything bad happen? Could I allow unwanted viruses or can people hack into the router, taking control of my computer? I haven't done this before, and I'm really scared something might happen if I don't do it correctly or if I unintentionally let a gateway for hackers and malware to invade my privacy.

Can't host a minecraft server?

So I'm trying to host a minecraft server with Hamachi and I get my friends to join perfectly fine but when they try to join my minecraft server it won't let them connect I got the right ip address and everything any ideas

Is it possible to transfer data from one minecraft account to another?

Me and my brother both share one minecraft account. I have decided to make a new one for myself. Now my only problem is all the servers that I donated to when me and my brother both shared one account, I do not have access to on my own account! I was really sad because all my money has been waisted because I have a new account. Please help me! Is there any way I could put all of my donations on my new account? Please only respond with serious answers!

Can I play somehow with my bro minecraft with one account?

Before I buy minecraft can me and my brother play minecraft together just us two in an offline server or through ethernet cable or somehow? :/

Added (1). latest minecraft

A free 24/7 minecraft host?

Free, 24/7, Bukkit, 30-100 slots (If possible )
Or would anyone be willing to host a server for me?

How to portforward on a Westell A90-750015-07Router (Minecraft)?

I'm running on a verizon network, and my Minecraft server is up and running. I can access it, but I'm wanting my friend to do so and he can't. I'm running on bukkit if that makes it any better. I really want to make this server public, so any type of help would be great!

Added (1). I tried those, but it doesn't seem to save/work. I'm not sure why.