High amount of RAM memory reserved for "cache" on startup

In the past couple of weeks I have been working to slim up my system (EndeavourOS XFCE install), removing unused packages and equally unused boot processes. However, it’s been a few days I have noticed that on boot my RAM memory is always partially occupied by "cache"d content (see picture below). This, after making sure to have rebooted without saving session.

Screenshot_2021-02-18_15-44-24

My current fear is that I may have disabled or tampered with some systemd process tasked with “clearing” the RAM, but it may as well be a totally unrelated issue.
I will nonetheless post below also the list of systemd processes

UNIT FILE                                                                 STATE           VENDOR PRESET
proc-sys-fs-binfmt_misc.automount                                         static          -            
-.mount                                                                   generated       -            
boot-efi.mount                                                            generated       -            
dev-hugepages.mount                                                       static          -            
dev-mqueue.mount                                                          static          -            
proc-fs-nfsd.mount                                                        static          -            
proc-sys-fs-binfmt_misc.mount                                             disabled        disabled     
sys-fs-fuse-connections.mount                                             static          -            
sys-kernel-config.mount                                                   static          -            
sys-kernel-debug.mount                                                    static          -            
sys-kernel-tracing.mount                                                  static          -            
tmp.mount                                                                 generated       -            
var-lib-machines.mount                                                    static          -            
var-lib-nfs-rpc_pipefs.mount                                              static          -            
cups.path                                                                 enabled         disabled     
gpm.path                                                                  static          -            
systemd-ask-password-console.path                                         static          -            
systemd-ask-password-wall.path                                            static          -            
session-2.scope                                                           transient       -            
adsl.service                                                              disabled        disabled     
alsa-restore.service                                                      static          -            
alsa-state.service                                                        static          -            
auditd.service                                                            disabled        disabled     
auth-rpcgss-module.service                                                static          -            
autorandr.service                                                         disabled        disabled     
autovt@.service                                                           alias           -            
avahi-daemon.service                                                      disabled        disabled     
avahi-dnsconfd.service                                                    disabled        disabled     
blk-availability.service                                                  disabled        disabled     
bluetooth-mesh.service                                                    disabled        disabled     
bluetooth.service                                                         disabled        disabled     
btrfs-scrub@.service                                                      static          -            
canberra-system-bootup.service                                            disabled        disabled     
canberra-system-shutdown-reboot.service                                   disabled        disabled     
canberra-system-shutdown.service                                          disabled        disabled     
colord.service                                                            static          -            
configure-printer@.service                                                static          -            
console-getty.service                                                     disabled        disabled     
container-getty@.service                                                  static          -            
cups-browsed.service                                                      disabled        disabled     
cups-lpd@.service                                                         static          -            
cups.service                                                              enabled         disabled     
dbus-org.freedesktop.hostname1.service                                    alias           -            
dbus-org.freedesktop.import1.service                                      alias           -            
dbus-org.freedesktop.locale1.service                                      alias           -            
dbus-org.freedesktop.login1.service                                       alias           -            
dbus-org.freedesktop.machine1.service                                     alias           -            
dbus-org.freedesktop.nm-dispatcher.service                                alias           -            
dbus-org.freedesktop.portable1.service                                    alias           -            
dbus-org.freedesktop.timedate1.service                                    alias           -            
dbus-org.freedesktop.timesync1.service                                    alias           -            
dbus.service                                                              static          -            
debug-shell.service                                                       disabled        disabled     
deluge-web.service                                                        disabled        disabled     
deluged.service                                                           disabled        disabled     
dhclient@.service                                                         disabled        disabled     
dhcpcd.service                                                            disabled        disabled     
dhcpcd@.service                                                           disabled        disabled     
display-manager.service                                                   alias           -            
dm-event.service                                                          static          -            
dmraid.service                                                            disabled        disabled     
e2scrub@.service                                                          static          -            
e2scrub_all.service                                                       static          -            
e2scrub_fail@.service                                                     static          -            
e2scrub_reap.service                                                      disabled        disabled     
ead.service                                                               disabled        disabled     
emergency.service                                                         static          -            
eos-update-notifier.service                                               masked          disabled     
fancontrol.service                                                        disabled        disabled     
fstrim.service                                                            static          -            
ftpd.service                                                              disabled        disabled     
getty@.service                                                            enabled         enabled      
git-daemon@.service                                                       static          -            
glances.service                                                           disabled        disabled     
gpm.service                                                               disabled        disabled     
gssproxy.service                                                          disabled        disabled     
haveged.service                                                           disabled        disabled     
healthd.service                                                           disabled        disabled     
hplip-printer@.service                                                    static          -            
initrd-cleanup.service                                                    static          -            
initrd-parse-etc.service                                                  static          -            
initrd-switch-root.service                                                static          -            
initrd-udevadm-cleanup-db.service                                         static          -            
ip6tables.service                                                         disabled        disabled     
iptables.service                                                          disabled        disabled     
iwd.service                                                               disabled        disabled     
kmod-static-nodes.service                                                 static          -            
krb5-kadmind.service                                                      disabled        disabled     
krb5-kdc.service                                                          disabled        disabled     
krb5-kpropd.service                                                       disabled        disabled     
krb5-kpropd@.service                                                      static          -            
ldconfig.service                                                          static          -            
lm_sensors.service                                                        disabled        disabled     
lock.service                                                              enabled         disabled     
logrotate.service                                                         static          -            
lvm2-lvmpolld.service                                                     masked          disabled     
lvm2-monitor.service                                                      masked          disabled     
lvm2-pvscan@.service                                                      masked          disabled     
ly.service                                                                disabled        disabled     
man-db.service                                                            static          -            
mdadm-grow-continue@.service                                              static          -            
mdadm-last-resort@.service                                                static          -            
mdmon@.service                                                            static          -            
mdmonitor.service                                                         static          -            
mkinitcpio-generate-shutdown-ramfs.service                                static          -            
ModemManager.service                                                      disabled        disabled     
modprobe@.service                                                         static          -            
named.service                                                             disabled        disabled     
nbd.service                                                               disabled        disabled     
nbd@.service                                                              disabled        disabled     
ndctl-monitor.service                                                     disabled        disabled     
netctl-auto@.service                                                      disabled        disabled     
netctl-ifplugd@.service                                                   disabled        disabled     
netctl-sleep.service                                                      disabled        disabled     
netctl-wait-online.service                                                disabled        disabled     
netctl.service                                                            disabled        disabled     
netctl@.service                                                           static          -            
NetworkManager-dispatcher.service                                         enabled         disabled     
NetworkManager-wait-online.service                                        masked          disabled     
NetworkManager.service                                                    enabled         disabled     
nfs-blkmap.service                                                        disabled        disabled     
nfs-idmapd.service                                                        static          -            
nfs-mountd.service                                                        static          -            
nfs-server.service                                                        disabled        disabled     
nfs-utils.service                                                         static          -            
nfsdcld.service                                                           static          -            
ninfod.service                                                            disabled        disabled     
nscd.service                                                              disabled        disabled     
nslcd.service                                                             masked          disabled     
ntpd.service                                                              disabled        disabled     
ntpdate.service                                                           disabled        disabled     
openvswitch.service                                                       masked          disabled     
paccache.service                                                          static          -            
pam_namespace.service                                                     static          -            
pcscd.service                                                             indirect        disabled     
pkgfile-update.service                                                    static          -            
plymouth-quit-wait.service                                                masked          disabled     
plymouth-quit.service                                                     masked          disabled     
plymouth-start.service                                                    masked          disabled     
polkit.service                                                            static          -            
ppp@.service                                                              disabled        disabled     
quotaon.service                                                           static          -            
rarpd@.service                                                            disabled        disabled     
rdisc.service                                                             disabled        disabled     
rdnssd@.service                                                           disabled        disabled     
reflector-auto.service                                                    disabled        disabled     
reflector.service                                                         disabled        disabled     
rescue.service                                                            static          -            
rfkill-block@.service                                                     disabled        disabled     
rfkill-unblock@.service                                                   disabled        disabled     
rlogin@.service                                                           static          -            
rpc-gssd.service                                                          static          -            
rpc-statd-notify.service                                                  static          -            
rpc-statd.service                                                         static          -            
rpcbind.service                                                           disabled        disabled     
rsh@.service                                                              static          -            
rsyncd.service                                                            disabled        disabled     
rsyncd@.service                                                           static          -            
rtkit-daemon.service                                                      disabled        disabled     
saned@.service                                                            static          -            
sddm.service                                                              enabled         disabled     
sensord.service                                                           disabled        disabled     
serial-getty@.service                                                     disabled        disabled     
shadow.service                                                            static          -            
smartd.service                                                            disabled        disabled     
snmpd.service                                                             disabled        disabled     
snmptrapd.service                                                         disabled        disabled     
sshd.service                                                              disabled        disabled     
sshdgenkeys.service                                                       static          -            
sssd.service                                                              masked          disabled     
sudo_logsrvd.service                                                      disabled        disabled     
svnserve.service                                                          disabled        disabled     
syncplay@.service                                                         disabled        disabled     
syslog.service                                                            masked          disabled     
system-update-cleanup.service                                             static          -            
systemd-ask-password-console.service                                      static          -            
systemd-ask-password-wall.service                                         static          -            
systemd-backlight@.service                                                static          -            
systemd-binfmt.service                                                    static          -            
systemd-bless-boot.service                                                static          -            
systemd-boot-check-no-failures.service                                    disabled        disabled     
systemd-boot-system-token.service                                         static          -            
systemd-coredump@.service                                                 static          -            
systemd-exit.service                                                      static          -            
systemd-firstboot.service                                                 masked          disabled     
systemd-fsck-root.service                                                 enabled-runtime disabled     
systemd-fsck@.service                                                     static          -            
systemd-halt.service                                                      static          -            
systemd-hibernate-resume@.service                                         static          -            
systemd-hibernate.service                                                 static          -            
systemd-homed-activate.service                                            disabled        disabled     
systemd-homed.service                                                     disabled        enabled      
systemd-hostnamed.service                                                 static          -            
systemd-hwdb-update.service                                               static          -            
systemd-hybrid-sleep.service                                              static          -            
systemd-importd.service                                                   static          -            
systemd-journal-catalog-update.service                                    static          -            
systemd-journal-flush.service                                             static          -            
systemd-journal-gatewayd.service                                          indirect        disabled     
systemd-journal-remote.service                                            indirect        disabled     
systemd-journal-upload.service                                            disabled        disabled     
systemd-journald.service                                                  static          -            
systemd-journald@.service                                                 static          -            
systemd-kexec.service                                                     static          -            
systemd-localed.service                                                   static          -            
systemd-logind.service                                                    static          -            
systemd-machine-id-commit.service                                         static          -            
systemd-machined.service                                                  static          -            
systemd-modules-load.service                                              static          -            
systemd-network-generator.service                                         disabled        disabled     
systemd-networkd-wait-online.service                                      enabled         disabled     
systemd-networkd.service                                                  disabled        enabled      
systemd-nspawn@.service                                                   disabled        disabled     
systemd-portabled.service                                                 static          -            
systemd-poweroff.service                                                  static          -            
systemd-pstore.service                                                    disabled        enabled      
systemd-quotacheck.service                                                static          -            
systemd-random-seed.service                                               static          -            
systemd-reboot.service                                                    static          -            
systemd-remount-fs.service                                                enabled-runtime disabled     
systemd-repart.service                                                    static          -            
systemd-resolved.service                                                  disabled        enabled      
systemd-rfkill.service                                                    masked          disabled     
systemd-suspend-then-hibernate.service                                    static          -            
systemd-suspend.service                                                   static          -            
systemd-sysctl.service                                                    static          -            
systemd-sysusers.service                                                  static          -            
systemd-time-wait-sync.service                                            disabled        disabled     
systemd-timedated.service                                                 static          -            
systemd-timesyncd.service                                                 enabled         enabled      
systemd-tmpfiles-clean.service                                            static          -            
systemd-tmpfiles-setup-dev.service                                        static          -            
systemd-tmpfiles-setup.service                                            static          -            
systemd-udev-settle.service                                               static          -            
systemd-udev-trigger.service                                              static          -            
systemd-udevd.service                                                     static          -            
systemd-update-done.service                                               static          -            
systemd-update-utmp.service                                               static          -            
systemd-user-sessions.service                                             static          -            
systemd-userdbd.service                                                   indirect        disabled     
systemd-vconsole-setup.service                                            static          -            
systemd-volatile-root.service                                             static          -            
talk.service                                                              indirect        disabled     
teamd@.service                                                            static          -            
teamviewerd.service                                                       disabled        disabled     
telnet@.service                                                           static          -            
tlp.service                                                               enabled         disabled     
udisks2-zram-setup@.service                                               static          -            
udisks2.service                                                           disabled        disabled     
updatedb.service                                                          static          -            
upower.service                                                            disabled        disabled     
usb_modeswitch@.service                                                   static          -            
usbmuxd.service                                                           static          -            
user-runtime-dir@.service                                                 static          -            
user@.service                                                             static          -            
uuidd.service                                                             indirect        disabled     
vpnc@.service                                                             disabled        disabled     
wpa_supplicant-nl80211@.service                                           disabled        disabled     
wpa_supplicant-wired@.service                                             disabled        disabled     
wpa_supplicant.service                                                    disabled        disabled     
wpa_supplicant@.service                                                   disabled        disabled     
xdm.service                                                               disabled        disabled     
xfs_scrub@.service                                                        static          -            
xfs_scrub_all.service                                                     static          -            
xfs_scrub_fail@.service                                                   static          -            
xl2tpd.service                                                            disabled        disabled     
ypbind.service                                                            masked          disabled     
machine.slice                                                             static          -            
system-systemd\x2dcryptsetup.slice                                        static          -            
user.slice                                                                static          -            
avahi-daemon.socket                                                       disabled        disabled     
cups-lpd.socket                                                           disabled        disabled     
cups.socket                                                               enabled         disabled     
dbus.socket                                                               static          -            
dm-event.socket                                                           static          -            
git-daemon.socket                                                         disabled        disabled     
krb5-kpropd.socket                                                        disabled        disabled     
lvm2-lvmpolld.socket                                                      masked          disabled     
pcscd.socket                                                              disabled        disabled     
rlogin.socket                                                             disabled        disabled     
rpcbind.socket                                                            disabled        disabled     
rsh.socket                                                                disabled        disabled     
rsyncd.socket                                                             disabled        disabled     
saned.socket                                                              disabled        disabled     
syslog.socket                                                             static          -            
systemd-coredump.socket                                                   static          -            
systemd-journal-gatewayd.socket                                           disabled        disabled     
systemd-journal-remote.socket                                             disabled        disabled     
systemd-journald-audit.socket                                             static          -            
systemd-journald-dev-log.socket                                           static          -            
systemd-journald-varlink@.socket                                          static          -            
systemd-journald.socket                                                   static          -            
systemd-journald@.socket                                                  static          -            
systemd-networkd.socket                                                   disabled        disabled     
systemd-rfkill.socket                                                     masked          disabled     
systemd-udevd-control.socket                                              static          -            
systemd-udevd-kernel.socket                                               static          -            
systemd-userdbd.socket                                                    disabled        enabled      
talk.socket                                                               disabled        disabled     
telnet.socket                                                             disabled        disabled     
uuidd.socket                                                              disabled        disabled     
dev-disk-by\x2duuid-5b752a67\x2de225\x2d42bc\x2dbd1e\x2d8840e53796d5.swap generated       -            
basic.target                                                              static          -            
blockdev@.target                                                          static          -            
bluetooth.target                                                          static          -            
boot-complete.target                                                      static          -            
cryptsetup-pre.target                                                     static          -            
cryptsetup.target                                                         static          -            
ctrl-alt-del.target                                                       alias           -            
default.target                                                            alias           -            
emergency.target                                                          static          -            
exit.target                                                               disabled        disabled     
final.target                                                              static          -            
first-boot-complete.target                                                static          -            
getty-pre.target                                                          static          -            
getty.target                                                              static          -            
graphical.target                                                          static          -            
halt.target                                                               disabled        disabled     
hibernate.target                                                          static          -            
hybrid-sleep.target                                                       static          -            
initrd-fs.target                                                          static          -            
initrd-root-device.target                                                 static          -            
initrd-root-fs.target                                                     static          -            
initrd-switch-root.target                                                 static          -            
initrd.target                                                             static          -            
kexec.target                                                              disabled        disabled     
local-fs-pre.target                                                       static          -            
local-fs.target                                                           static          -            
machines.target                                                           disabled        enabled      
multi-user.target                                                         static          -            
network-online.target                                                     static          -            
network-pre.target                                                        static          -            
network.target                                                            static          -            
nfs-client.target                                                         disabled        disabled     
nss-lookup.target                                                         static          -            
nss-user-lookup.target                                                    static          -            
paths.target                                                              static          -            
poweroff.target                                                           disabled        disabled     
printer.target                                                            static          -            
reboot.target                                                             disabled        enabled      
remote-cryptsetup.target                                                  disabled        enabled      
remote-fs-pre.target                                                      static          -            
remote-fs.target                                                          enabled         enabled      
rescue.target                                                             static          -            
rpc_pipefs.target                                                         static          -            
rpcbind.target                                                            static          -            
shutdown.target                                                           static          -            
sigpwr.target                                                             static          -            
sleep.target                                                              static          -            
slices.target                                                             static          -            
smartcard.target                                                          static          -            
sockets.target                                                            static          -            
sound.target                                                              static          -            
suspend-then-hibernate.target                                             static          -            
suspend.target                                                            static          -            
swap.target                                                               static          -            
sysinit.target                                                            static          -            
system-update-pre.target                                                  static          -            
system-update.target                                                      static          -            
time-set.target                                                           static          -            
time-sync.target                                                          static          -            
timers.target                                                             static          -            
umount.target                                                             static          -            
usb-gadget.target                                                         static          -            
btrfs-scrub@.timer                                                        disabled        disabled     
e2scrub_all.timer                                                         disabled        disabled     
fstrim.timer                                                              enabled         disabled     
logrotate.timer                                                           disabled        disabled     
man-db.timer                                                              disabled        disabled     
mdadm-last-resort@.timer                                                  static          -            
paccache.timer                                                            disabled        disabled     
pkgfile-update.timer                                                      disabled        disabled     
reflector-auto.timer                                                      disabled        disabled     
reflector.timer                                                           disabled        disabled     
shadow.timer                                                              static          -            
systemd-tmpfiles-clean.timer                                              static          -            
updatedb.timer                                                            static          -            
xfs_scrub_all.timer                                                       disabled        disabled     

378 unit files listed.

Thank you in advance for any tip you could give me about what could be misbehaving with my setup

This is a good thing.

https://www.linuxatemyram.com

2 Likes

I do know the trope, and indeed agree with you on the fact that caching is good.

My surprise was at seeing this much caching before opening any software which, unless I am mistaken, did not use to happen before my fiddling with the system :slight_smile:
Is there maybe a way for me to tell what exactly is my system caching?

Display manager, desktop environment, themes, wallpaper, icons, … there are plenty of processes launched and data accessed before your user starts launching applications.

https://searx.garudalinux.org/search?q=linux%20cache%20contents&categories=general&language=en-US

https://www.thomas-krenn.com/en/wiki/Linux_Page_Cache_Basics

2 Likes

Thank you very much for your reply.
So, there seems to be no way to check what is cached (as in, listing the content), but only to check individual files / executables against the cache