Minecraft 1.7.10 modpack server crashes?

After a while, I'm not on the server on it. After a reboot only a short time and I have connection lost timed out again. This is a Nitrado server and he has more than enough ram (6gb). It's the same with the other players. The console always says: [Server thread / WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4448ms behind, skipping 88 tick (s)

This indicates that many chunks are permanently loaded and working. Technology Modpack? If so, which?

Evtl but just do not reach the 6gb Ram. This may not be enough, depending on the modpack.

All in all, that just means that your server is overloaded, with whatever?! Yesterday I had the same problem with one of my 4 servers. I've made a n terminal and watched the season. The problem occurred when I started to use dynmap to start a fullrender. The message was irregular but repeated…

then have time with htop the total utilization observed and all other processes closed. The java season of mc had a tendency pendulum value of 78 to 191% at the cpu (thus not even 2 cores full) 23% ram (12gb had the mc server virtually available) and the virt was at 11.9 to 12.1gb… That's more than blatant! The problem did not occur until dynmap resumed rendering.
this has flooded the application in the virtual memory so that the server itself did not come with the calculation afterwards. Reason for such things can be inconsistent data wi defective chunks or the like. The pluguin dynmap is also just programmed from the finest, if it is also fun

i first thought it's a resource problem of swap or linux in general. So it usb ssd tuned and it again on my desktop computer problems because 64gb ram 32 processors and hundreds of gigabytes of ssd memory. Exactly the same… It is up to dynmap and the server itself. I suspect you have somewhere a defective chunk or other consistency errors in your map or the server. ^^

ps: it does not necessarily indicate that, as mentioned below, many chunks have perm load. It does not have to hang with the ram.
but it CAN… Should not be ignored

At nitrado it always stands at 40-50%. Why are so many chunks loading? How can you reduce this?

How do I repair chunks and how do I find out which ones are defective?

Which are defective is usually in the server launch protocol. [Warn.] Defectiv chunk detected -266.134 or so

you can repair the things with mc edit or mc region fixer. Can also scan after