[xubuntu-users] magic processes

[Ralf Mardorf]

On Wed, 11 Jul 2018 22:39:47 -0400, lefty wrote:
>Do all processes start in /tmp?

No, /tmp is a directory mainly used by user session specific processes.
Depending on how you or your distros installer set up your Linux /tmp
is a tmpfs, IOW it's used RAM, not drive space.

[rocketmouse at archlinux ~]$ lsof | grep /tmp/
dbus-daem   779                 rocketmouse    5u     unix 0x00000000ee21ecbc       0t0      20991 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse    8u     unix 0x000000002a45c64b       0t0      20996 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse    9u     unix 0x00000000886c5a99       0t0      21027 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse   10u     unix 0x000000005433d3d3       0t0     136996 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse   11u     unix 0x00000000d0730f30       0t0      21231 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse   12u     unix 0x0000000084c05853       0t0      21611 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse   13u     unix 0x000000006b42e0f4       0t0     137938 @/tmp/dbus-ZVZg81Bcrj type=STREAM
dbus-daem   779                 rocketmouse   14u     unix 0x0000000028de1d00       0t0     288171 @/tmp/dbus-ZVZg81Bcrj type=STREAM
claws-mai  4848                 rocketmouse    4u     unix 0x00000000240a3e76       0t0     137873 /tmp/claws-mail-1000/d50dca64f26ba118a25bee02366fef2f type=STREAM
gksudo     4917                 rocketmouse    6w      REG               0,45        54     137063 /tmp/libgksu-vuJooy/.Xauthority
roxterm   26398                 rocketmouse   10u      REG               0,45   2162688     288210 /tmp/#288210 (deleted)
roxterm   26398                 rocketmouse   11u      REG               0,45    393216     288211 /tmp/#288211 (deleted)
roxterm   26398 26399 gmain     rocketmouse   10u      REG               0,45   2162688     288210 /tmp/#288210 (deleted)
roxterm   26398 26399 gmain     rocketmouse   11u      REG               0,45    393216     288211 /tmp/#288211 (deleted)
[rocketmouse at archlinux ~]$ df -h | grep tmpfs
tmpfs           3.9G  4.0K  3.9G   1% /dev/shm
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
tmpfs           3.9G  364K  3.9G   1% /tmp
tmpfs           786M   60K  786M   1% /run/user/1000

>Is systemd drunk?

No, systemd has got pros and cons, but what you experience is not
caused by systemd. As already pointed out by the smartmontools example,
it's Ubuntu's policy to start the service. It doesn't matter if the
init system is systemd or anything else, e.g. upstart. If you install
the package smartmontools you need to disable smartd, if you don't want
that it does run, since Ubuntu's policy says so. If you run Arch Linux,
it's vice versa, a user needs to enable smartd and similar things.

It's good practise to read and compare the distros' policies before
using a distro.