什么是/ dev / mapper / vg_root-lv_root目录？为什么我的docker依赖于这个目录？

Question

    du

lists

 Filesystem 1K-blocks Used   Available Use% Mounted on

 /dev/mapper/vg_root-lv_root 38929872   36450548     503672  99% /

 tmpfs 4025936               0    4025936   0% 

 /dev/shm /dev/sda1 53871    39618     201146  17% /boot

 xxx.in:/vol/software/arch*  653053184  408978688  244074496  63% /usr/software

 xxxx:/users003/gopir        3435973888 1024638080 2411335808  30% /u/gopir

I am not able to format it. In this case, my /dev/mapper/vg* is full. But i have space in my directory. How should i make use of my space? Why do my docker depends on this space rather than my space? Due to this, i get write error. I referred this but it doesn't help me. And what is this directory?

Answer 1

With below command, I managed to find which folder this drive maps to.

tree -LP 1 /dev/mapper/vg_os-lv_root

After that I was able to move folder to different drive (which have more space), in my case it was /var/lib/docker

You might have to install tree package using command yum install tree if not available by default.

Answer 2

Docker by design has a flaw OOB. It gets mounted on aufs by default. The better alternative to the same is to use Device mapper with lvm configured.

[ https://docs.docker.com/engine/userguide/storagedriver/device-mapper-driver/#write-examples][1]

So in your case it seems you already have device mapper in place. So I suggest you create and extra loop-lvm config and add to your existing Volume Group based on the above documentation.