ECS clean disk device space files

cd /opt-bash: cannot create temp file for here-document: No space left on device

df -h

Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        7.7G     0  7.7G   0% /dev
tmpfs           7.7G     0  7.7G   0% /dev/shm
tmpfs           7.7G  520K  7.7G   1% /run
tmpfs           7.7G     0  7.7G   0% /sys/fs/cgroup
/dev/vda1        59G   46G   11G  81% /
tmpfs           1.6G  4.0K  1.6G   1% /run/user/0

du -sh /opt/applications/*

8.0K    /opt/applications/a
5.8G    /opt/applications/b
23G     /opt/applications/c
24K     /opt/applications/d
28K     /opt/applications/e
6.7G    /opt/applications/f

 du -sh /opt/applications/production/*

12G     /opt/applications/production/a
8.8G    /opt/applications/production/b
1.1G    /opt/applications/production/c
873M    /opt/applications/production/d
479M    /opt/applications/production/e

Step by step, confirm that a specific directory can be temporarily deleted, and conduct file content governance at the same time