Bei der Logsuche kam das heraus:
root@Server:~# ls -l /var/log
total 33084
-rw-rw---- 1 system log 50950 Jan 2 21:10 apparmor.log
-rw-rw---- 1 system log 148774 Jan 2 21:11 appindex.log
-rw-rw---- 1 system log 1472 Jan 2 21:07 audio_debug_msg
-rw-r----- 1 root log 814093 Jan 4 12:20 auth.log
-rw-rw---- 1 system log 30563 Jan 2 20:57 bash_err.log
-rw-rw---- 1 system log 9606 Jan 4 12:20 bash_history.log
-rw-rw---- 1 system log 5125 Jan 2 21:09 datascrubbing.log
-rw-r--r-- 1 root root 7478 Jan 1 17:47 DeviceBusyList
-rw-r--r-- 1 root root 54568 Jan 3 10:35 disk_health_information.json
-rw-rw---- 1 system log 387392 Jan 2 21:10 disk.log
-rw-r--r-- 1 root root 0 Dec 28 2016 disk_log.xml
-rw-r--r-- 1 root root 1643 Jan 2 21:10 disk_overview.xml
drwxr-xr-x 2 root root 4096 Jan 3 12:43 diskprediction
-rw-rw-rw- 1 root root 2247 May 28 2018 disk_smart_test_log.xml
-rw-r--r-- 1 root root 600898 Jan 2 21:10 dmesg
-rw-r--r-- 1 root root 47960 Jan 19 2018 dmesg.1.xz
-rw-r--r-- 1 root root 567 Dec 28 15:32 dms.log
-rw-r--r-- 1 root root 158099 Jan 2 21:07 dpkg.log
-rw-r--r-- 1 root root 109667 Jan 2 21:07 dpkg_upgrade.log
-rw-rw---- 1 system log 1169221 Jan 2 21:10 esynoscheduler.log
-rw-rw---- 1 system log 2629988 Jan 2 21:10 fileindexd.log
-rw-rw---- 1 system log 67428 May 9 2018 fileindexd.log.1.xz
-rw-rw---- 1 system log 51404 May 4 2018 fileindexd.log.2.xz
-rw-rw---- 1 system log 59628 Mar 11 2018 fileindexd.log.3.xz
-rw-rw---- 1 system log 76364 Feb 12 2018 fileindexd.log.4.xz
drwxr-xr-x 2 root root 4096 Feb 5 2018 fsck
-rw-rw---- 1 system log 3846 Sep 8 2017 ha.log
drwxr-xr-x 2 root root 4096 Feb 13 2017 healthtest
-rw-rw---- 1 system log 589023 Jan 2 21:10 iscsi.log
-rw-r--r-- 1 root root 5483169 Jan 4 12:11 JDownloader.log
-rw-rw---- 1 system log 1159812 Jan 2 21:09 kern.log
drwxr-xr-x 2 admin users 4096 Jun 19 2017 lighttpd
-rw-rw---- 1 system log 6020569 Jan 3 09:20 messages
drwxr-x--- 2 http root 4096 Dec 28 2016 nginx
-rw-rw---- 1 system log 16103 Jun 21 2017 php56-fpm.log
-rw-rw---- 1 system log 218055 Jan 2 21:10 postgresql.log
-rw-rw---- 1 system log 298258 Jan 4 12:15 router.log
drwxr-xr-x 2 root root 4096 Dec 28 2016 samba
-rw-rw---- 1 system log 1383134 Jan 2 21:10 scemd.log
drwxr-x--- 2 root root 4096 Oct 10 18:36 selfcheck
-rw-rw---- 1 system log 4610 Dec 27 13:35 sfdisk.log
-rw-r--r-- 1 root root 140 Jan 2 13:07 smart_extend_log
-rw-r--r-- 1 root root 140 Dec 28 00:02 smart_quick_log
drwxr-xr-x 2 root root 4096 Dec 31 01:24 smart_result
-rw-rw-rw- 1 root root 21975 Jan 2 21:09 space_operation_error.log
-rw-r--r-- 1 root root 12899 Jan 2 21:10 synocmsclient.log
-rw-rw---- 1 system log 3846245 Jan 2 21:10 synocontentextractd.log
-rw-rw---- 1 system log 57388 Sep 8 2017 synocontentextractd.log.1.xz
-rw-rw---- 1 system log 44952 Feb 15 2017 synocontentextractd.log.2.xz
-rw-rw---- 1 system log 37388 Jan 28 2017 synocontentextractd.log.3.xz
-rw-rw---- 1 system log 52928 Jan 27 2017 synocontentextractd.log.4.xz
-rw-rw---- 1 system log 6844 Feb 22 2017 synocontentsearchd.log
-rw-r--r-- 1 root root 979326 Jan 4 11:16 synocrond-execute.log
-rw-rw---- 1 system log 214986 Jan 2 21:10 synocrond.log
-rw-rw---- 1 system log 940008 Jan 2 21:18 synoelasticd.log
-rw-rw---- 1 system log 80504 Oct 26 19:53 synoelasticd.log.1.xz
-rw-rw---- 1 system log 162144 Feb 10 2018 synoelasticd.log.2.xz
-rw-rw---- 1 system log 400148 Oct 5 2017 synoelasticd.log.3.xz
-rw-rw---- 1 system log 68284 Jul 30 2017 synoelasticd.log.4.xz
-rw-rw---- 1 system log 172935 Jan 2 21:07 synofeasibilitycheck.log
-rw-rw---- 1 system log 1788955 Dec 29 03:03 synoindex.log
-rw-r--r-- 1 root root 8210 Nov 18 2017 synoinfo.conf.bad
drwxr-x--- 2 system log 4096 Jan 4 12:19 synolog
-rw-r--r-- 1 root root 2497102 Jan 2 21:11 synopkg.log
-rw-rw---- 1 system log 22800 Jan 2 21:07 synopoweroff.log
-rw------- 1 root root 73117 Jan 2 21:10 synorelayd.log
-rw-rw---- 1 system log 1398 Jan 1 17:05 synoscheduler.log
-rw-rw---- 1 system log 221718 Jan 4 12:15 synoservice.log
-rw-rw---- 1 system log 115952 Dec 25 16:31 synoservice.log.1.xz
-rw-rw---- 1 system log 4469 Jan 2 21:07 synotifyd.log
-rw-r--r-- 1 root root 13981 Jan 2 21:07 synoupdate.log
-rw-rw---- 1 system log 67389 Jan 2 21:09 syslog.log
-rw-rw---- 1 system log 6244 Jan 2 21:00 sysnotify.log
drwxr-xr-x 2 root root 4096 Jan 2 19:59 upstart
Ist da jetzt etwas dabei was "besonders schlimm" ist? Wenn nicht würde ich gerne vermeiden da noch groß mehr drin rumzuwerkeln da ihr ja schon ganz richtig bemerkt hab das ich wenig Ahnung in dem Bereich habe.