I am very inexperienced in Linux server administration and I got suck... I have a VM running under CentOS centos-release-7-6.1810.2.el7.centos.x86_64. On this VM I am running a test installation of an ActiveMQ-InfluxDB-Grafana stack.
Now my system ran out of disk space. "df" shows the follwing:
/dev/mapper/vg_main-root 16766976 15605268 1161708 94% /
devtmpfs 8116348 0 8116348 0% /dev
tmpfs 8133376 0 8133376 0% /dev/shm
tmpfs 8133376 778780 7354596 10% /run
tmpfs 8133376 0 8133376 0% /sys/fs/cgroup
/dev/sda1 1007896 189228 767468 20% /boot
tmpfs 1626676 12 1626664 1% /run/user/42
tmpfs 1626676 4 1626672 1% /run/user/0
/dev/mapper/vg_main-influxdb 61856248 32992 61823256 1% /var/lib/influxdb/data
This is the state after having deleted all the InfluxDB-files, which consumed 20G on volume-group vg_main_influxdb. I cleaned as well temporary files on vg_main-root, which brought down the disk usage from 100% to the 94% you see here.
Command vgs shows:
VG #PV #LV #SN Attr VSize VFree
vg_main 1 3 0 wz--n- <79.02g 0
furthermore we have
[root@vmla032 /]# du -h --max-depth=1
184M ./boot
0 ./dev
0 ./proc
761M ./run
0 ./sys
42M ./etc
120M ./root
1.1G ./var
36K ./tmp
4.2G ./usr
360K ./home
0 ./mnt
747M ./opt
0 ./srv
7.0G .
Result of pvdisplay
[root@vmla032 /]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name vg_main
PV Size 79.02 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 20229
Free PE 0
Allocated PE 20229
Another symptom is that vg_main-root gets filled with data by some process and runs out of disk space. For example log data seems to go there as disk space got freed whe I deleted these files.
How do I get more space? How do I find out which processes clog vg_main-root?