Why are these using swap when I have plenty of free ram?

[Robert Heller]

At Fri, 08 Nov 2019 15:42:18 -0600 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> The below processes are using swap for some reason:
> 
> User     Name                         Swap
> root     courierlogger                  76
> daemon   atd                           188
> root     acpid                         116
> avahi    avahi-daemon                  300
> root     lvmetad                       208
> root     authdaemond                    12
> root     osspd                         124
> root     cron                          184
> root     wpa_supplicant                480
> systemd-timesync systemd-timesy        460
> systemd-resolve systemd-resolv         492
> root     irqbalance                     44
> avahi    avahi-daemon                  220
> root     systemd-logind                424
> root     smartd                        564
> root     accounts-daemon               312
> syslog   rsyslogd                      404 
> gdm      (sd-pam                      1440
> root     systemd-udevd                1036
> messagebus dbus-daemon                 252
> chris    (sd-pam                       188
> root     systemd                       196
> root     networkd-dispat              3344
> root     udisksd                       252
> root     systemd-journal               340
>   
>  total        used        free      shared  buff/cache   available
> Mem15351148  6475100     3012432    407808   5863616     5408332
> Swap:       4089852       53248     4036604
> 
> Before anyone asks I've had a swap partition for years dating way back
> so I've just never removed it. It's only been a month or so that swap
> has started being used and I have no idea why with plenty of free ram.
> Of course it's not hurting anything however I'm really curious as to
> why these processes are using it. Ubuntu version and kernel version are
> in my sig.

The kernel will move "unused" portions of process memory to swap from time to 
time, usually because the process memory has had no access in a low while.  
This partitularly happens when memory becomes "tight" (too little free RAM).

> 

-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
heller at deepsoft.com       -- Webhosting Services