Well, I noticed that the server uses a lot of RAM, too.
Looking at the screenshot Serenity linked, I saw that his server doesn't have SWAP.
I'm running the current "stable" release from Steam on Debian-Testing and got my game to an unplayable state, once the game is started, my computer is using 4 GB of RAM + 2 GB SWAP.
I got the server to crash, too. It wrote a few things in the log:
Tue Feb 28 12:37:28 2017| Player unbekannt1984 moved to sector (189:-195)from (188:-198) server time taken for change: 619ms
Tue Feb 28 12:37:28 2017| Creating sector at (194:-195)
Tue Feb 28 12:37:28 2017| Creating sector at (187:-188)
Tue Feb 28 12:37:28 2017| scheduled save for sector (188:-198), 0x7faf880008c0, entities: 2521
Tue Feb 28 12:37:28 2017| saving sector (188:-198)
Tue Feb 28 12:37:29 2017| Generating new content for sector (194:-195)
Tue Feb 28 12:37:29 2017| Generating new content for sector (187:-188)
Tue Feb 28 12:37:31 2017| sector (188:-198) saved to "/home/torsten/.avorion/galaxies/blubb/sectors/188_-198"
Tue Feb 28 12:37:51 2017| Warning, can't keep up, skipping 1 frames...
Tue Feb 28 12:39:30 2017| scheduled save for sector (194:-195), 0x7faf380009b0, entities: 915
Tue Feb 28 12:45:32 2017| Triggered saving of all server data.
Tue Feb 28 12:45:35 2017| saving sector (194:-195)
Tue Feb 28 12:46:30 2017| sector (194:-195) saved to "/home/torsten/.avorion/galaxies/blubb/sectors/194_-195"
Tue Feb 28 12:47:27 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x6322cf 2>&1
Tue Feb 28 12:48:07 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x63260a 2>&1
Tue Feb 28 12:48:07 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x655848 2>&1
Tue Feb 28 12:48:07 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x6b4d35 2>&1
Tue Feb 28 12:48:08 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x92d5d3 2>&1
Tue Feb 28 12:48:08 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x682057 2>&1
Tue Feb 28 12:48:08 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0xad63dd 2>&1
Tue Feb 28 12:48:09 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0xad9394 2>&1
Tue Feb 28 12:48:09 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0xad6b69 2>&1
Tue Feb 28 12:48:09 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0xad5a59 2>&1
Tue Feb 28 12:48:10 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0xad6e91 2>&1
Tue Feb 28 12:48:11 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0xacd5e8 2>&1
Tue Feb 28 12:48:11 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x637ed1 2>&1
Tue Feb 28 12:48:12 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x6942bf 2>&1
Tue Feb 28 12:48:12 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x640544 2>&1
Tue Feb 28 12:48:12 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x640766 2>&1
Tue Feb 28 12:48:12 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x64b0cf 2>&1
Tue Feb 28 12:48:13 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x64b428 2>&1
Tue Feb 28 12:48:13 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x7fafae203290 2>&1
Tue Feb 28 12:48:13 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x7fafada18424 2>&1
Tue Feb 28 12:48:14 2017| addr2line -i -e /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer 0x7fafad75b9bf 2>&1
Tue Feb 28 12:48:20 2017| 140392376772352 failed to aquire /home/koonschi/buildbot/slave/steamrt-release/build/SpaceServer/Database/FactionDatabase.cpp: 485, accessMutex after 1000000 tries
Tue Feb 28 12:48:20 2017| backtrace() returned 22 addresses
Tue Feb 28 12:48:20 2017| [bt] #1 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN11MutexLockerISt15recursive_mutexLb0EE4lockEv+0xff) [0x6322cf]
Tue Feb 28 12:48:20 2017| [bt] #2 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN11MutexLockerISt15recursive_mutexLb0EEC2ERS0_RKSsS4_+0x6a) [0x63260a]
Tue Feb 28 12:48:20 2017| [bt] #3 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN15FactionDatabase11findFactionEi+0xd8) [0x655848]
Tue Feb 28 12:48:20 2017| [bt] #4 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN6Galaxy10getFactionEi+0x45) [0x6b4d35]
Tue Feb 28 12:48:20 2017| [bt] #5 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZNK21ScriptFactionAccessor24getHomeSectorCoordinatesEv+0x13) [0x92d5d3]
Tue Feb 28 12:48:20 2017| [bt] #6 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN27ScriptFaction_script_detail31member_getHomeSectorCoordinatesEP9lua_State+0x37) [0x682057]
Tue Feb 28 12:48:20 2017| [bt] #7 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer() [0xad63dd]
Tue Feb 28 12:48:20 2017| [bt] #8 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer() [0xad9394]
Tue Feb 28 12:48:20 2017| [bt] #9 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer() [0xad6b69]
Tue Feb 28 12:48:20 2017| [bt] #10 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer() [0xad5a59]
Tue Feb 28 12:48:20 2017| [bt] #11 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer() [0xad6e91]
Tue Feb 28 12:48:20 2017| [bt] #12 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(lua_pcallk+0x58) [0xacd5e8]
Tue Feb 28 12:48:20 2017| [bt] #13 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN6Script6doCallISt6vectorI8LuaValueSaIS2_EEEET_RKSsj+0xf1) [0x637ed1]
Tue Feb 28 12:48:20 2017| [bt] #14 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN22SectorContentGenerator15generateContentERKSs+0x26f) [0x6942bf]
Tue Feb 28 12:48:20 2017| [bt] #15 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN22CreateSectorWorkPacket8generateEv+0x2f4) [0x640544]
Tue Feb 28 12:48:20 2017| [bt] #16 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN22CreateSectorWorkPacket3runEv+0x196) [0x640766]
Tue Feb 28 12:48:20 2017| [bt] #17 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZN2ut6WorkerINS_5queueISt10shared_ptrINS_10WorkPacketEEEEE16workSinglePacketEv+0x28f) [0x64b0cf]
Tue Feb 28 12:48:20 2017| [bt] #18 /home/torsten/.steam/steam/steamapps/common/Avorion/bin/AvorionServer(_ZNSt6thread5_ImplISt12_Bind_simpleIFN2ut6WorkerINS2_5queueISt10shared_ptrINS2_10WorkPacketEEEEEEvEEE6_M_runEv+0x18) [0x64b428]
Tue Feb 28 12:48:20 2017| [bt] #19 /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0xba290) [0x7fafae203290]
Tue Feb 28 12:48:20 2017| [bt] #20 /lib/x86_64-linux-gnu/libpthread.so.0(+0x7424) [0x7fafada18424]
Tue Feb 28 12:48:20 2017| [bt] #21 /lib/x86_64-linux-gnu/libc.so.6(clone+0x5f) [0x7fafad75b9bf]
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| crtstuff.c:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| crtstuff.c:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| crtstuff.c:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| crtstuff.c:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| crtstuff.c:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:?
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:0
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:0
Tue Feb 28 12:48:20 2017| ERROR: ld.so: object '/home/torsten/.steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Tue Feb 28 12:48:20 2017| ??:0
Tue Feb 28 12:48:20 2017|
Tue Feb 28 12:49:09 2017| Server is shutting down.
Tue Feb 28 12:49:09 2017|
