Bukkit

@juloo65

Not true, Worldborder is extremely lightweight with the border monitoring routine. Pretty much any other plugin you can name is more resource intensive. Look elsewhere for a scapegoat.

@ShakyTom

When counting chunks as it trims them it doesn't currently differentiate between existing and non-existent chunks; it just goes by the number of chunks available in the region file which are outside the border. I'd considered reworking it so that it can give a more accurate accounting of only the chunks which are actually trimmed, but I just don't have time for it.

What tool are you using to create the map?

@Pr07o7yp3

Last I checked each world region file maxes out usually at a bit over 5 MB, and a region is 512x512 blocks (32x32 chunks). The size might have gone up since I checked and with heavy modification of a region it might need more data than that, so to be on the safe side you might figure ~ 6 MB per 512x512 block region (262144 blocks total). As before, I'll let you do the math from there.

@ShakyTom

If so, you should have received an error in your server log/console during the Trim process. I've already covered that and the other possibilities in my last response to you.
If you're telling me none of those is the case, you'll need to provide me with a lot more information (and possibly a copy of the world so I can take a look myself).

@Pr07o7yp3

Radius 20000 = 40000 x 40000 block area for square border. A bit less for round border, of course (search "calculate area of circle given radius" or similar in Google). Chunks are 16 x 16 blocks. I'll leave it to you to figure it out from there.

@QweSteR2221

You would need to provide a bit more information than that. Are you trying to use custom world generators? IIRC you need to specify those in bukkit.yml for Bukkit and by extension WorldBorder's Fill process to know which world generator to use on a given world.
If that's not your problem, again, more info would be needed as to what problem you're actually having.

@diannetea

Partial fill? Not as such, though you can simply set the border to a smaller radius temporarily and run the Fill command, then increase the border radius again afterward.

@alexander_gq

I doubt it. If you're getting a bluescreen in Windows, that generally indicates hardware or driver problems.

@ShakyTom

Then I'd guess that whatever map renderer you are using is presumably caching the data and you need to clear its cache.

I've already explained that the Trim command goes through the actual region files and covers every single chunk ever generated for the world. If chunks were left behind, you would have a nice error message in your server log/console explaining that a region file could not be deleted. If no such message showed up when you ran the Trim process, it will have succeeded and the cause of your problem is with whatever you are using to render the map.

@ShakyTom

The Trim command runs on every region file in your world, so it gives full coverage of everything.

Are you using DynMap? If so, shut down and restart your server to clear its memory cache, then run a fullrender in DynMap. If you're still seeing those errant chunks, clear your browser (IE, Chrome, Firefox, whatever) cache.

@LordChaos2

Is your server log truncated? I would need the full stack trace from that for it to make any sense. The shortened error message you've posted doesn't have any stack trace provided, so there's no telling what might cause it or even whether it's WorldBorder at fault (unlikely).
Also, certain newer releases of CraftBukkit seem to have occasional random errors like that one, which is much more likely the cause of your error.

People having problems with the trim command, please read this post and provide the requested information:
http://dev.bukkit.org/server-mods/worldborder/tickets/25-trim-errors/#c4
Since I can't reproduce it and most people don't encounter it, I would need as much information on your setup and the circumstances of the error as you can provide.