World Generation - Lag Issues

[Wader]

Hello,

I'm currently running a DireWolf20 server with a max of about 6 people on at anyone time, with about 10 overall players. This is running on an xen vm (from my own dedi) with access to 4 cores of an Xeon E5-1620, 16GB RAM and an Intel SSD 320.

I've looked through a couple of threads previously and edited some of the JVM args which has worked well and the server has suffered from little lag since, however when new map is being generated quite bad lag occurs. Mystcraft age books are disabled so only ops can spawn new worlds. We currently only have 1 world spawned, a void world.

However i'm now wanting to generate a mining world so the overworld isnt getting torn up all the time, upon jumping to this world the server just stalls running at 100% CPU and no new files are being generated in the region folder for the age and you cant even connect to the server until forcefully killed and rebooted.

This is my launch command

screen -dmS ftb java -server -Xincgc -Xmx3G -Xms2G -Xmn1G -XX:NewRatio=2 -XX:CMSFullGCsBeforeCompaction=1 -XX:SoftRefLRUPolicyMSPerMB=2048 -XX:+CMSParallelRemarkEnabled -XX:+UseParNewGC -Xnoclassgc -XX:+UseFastAccessorMethods -XX:CMSInitiatingOccupancyFraction=90 -XX:+UseConcMarkSweepGC -XX:UseSSE=3 -XX:+UseCMSCompactAtFullCollection -XX:ParallelGCThreads=2 -XX:+AggressiveOpts -XX:ReservedCodeCacheSize=1G -cp ftbserver.jar -jar ftbserver.jar nogui

Any advice here?

Edit: After being left for about 30 mins its finally generated the mystcraft age and server is playable, but i would like to get to the bottom of the problem so this doesnt happen every time we want to generate a new world.

 

[Tsugaga]

Why would the launch file have any effect post launch? What is happening during world generation? Data is being written. What limits the amount of data being written? The cpu and your hdd/ssd r/w speed. I would assume you're using an hdd. hdd's r/w speeds are very very bad for FTB. I suggest getting an ssd if that's the case.

 

[Wader]

Why would the launch file have any effect post launch?

Because that determines what resources the JVM has access to? and seeing as i dont exactly know much about that, something i set might be causing it. I just put together that launch command from bits and pieces i found in other threads i read through a while ago.

What is happening during world generation? Data is being written. What limits the amount of data being written? The cpu and your hdd/ssd r/w speed. I would assume you're using an hdd. hdd's r/w speeds are very very bad for FTB. I suggest getting an ssd if that's the case.

Detailed all the in thread. pls read.

 

[Tsugaga]

You don't even need it... Just leave it blank.