I used vnc to connect to VPS and debian installer to install debian 8, at least I was thinking it is net installation, about 300MB, but as you see below, it has 825MB and I chose only ssh server installation (tasksel), no web server, desktop, print or anything else. I wanted to do it later manually, by myself.
I chose also partitioning, vda for filesystem and swap, but here below I don't see swap listen anywhere and I never chose /dev /run and so on, I chose only vda1 as / mount point and swap, I didn't crate any additional partitions (tmpfs). so, why i have all this listed? I didn't create it during installation.
/etc/apt# df -H
Filesystem Size Used Avail Use% Mounted on
/dev/vda1 1.1T 825M 975G 1% /
udev 11M 0 11M 0% /dev
tmpfs 3.0G 8.7M 3.0G 1% /run
tmpfs 7.4G 0 7.4G 0% /dev/shm
tmpfs 5.3M 0 5.3M 0% /run/lock
tmpfs 7.4G 0 7.4G 0% /sys/fs/cgroup
consequently VPS is spending 280MB RAM and I just installed ssh server. I have crowd of kworker, migration, watchdog, writeback processes, I don't know if they are important, can I kill it? what is kworker, migration, khelp, watchdog, writeback?
I think basic debian installation should spend less than 100MB RAM. this eats 280MB.