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Daemon Count Calculator

Calculate the number of background daemons running and their aggregate resource usage.

About Daemon Count Calculator

'Enabled' (systemctl is-enabled) means a unit is configured to start automatically at boot; 'running' (systemctl is-active) means it's actually active right now — the two lists commonly diverge because of oneshot-type units (which run once and exit successfully, e.g. one-time setup tasks), condition-gated units (After=/ConditionPathExists= etc. that only start under specific circumstances), or units that failed to start. Estimating aggregate RSS across running daemons (average per-daemon footprint × running count) gives a rough baseline memory cost of 'always-on background services' separate from application workload memory, useful for right-sizing minimal-footprint systems or containers.

Formula

Estimated total daemon memory

total_rss = running_daemons × avg_rss_per_daemon

n_{run}
currently running daemon count
"\\bar{r}"
average RSS per daemon

Worked example

With the default values below, Daemon Count Calculator returns Estimated Total Daemon RSS (MB) of 684.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Enabled Daemons/Servicesminimum 0
45
Currently Running Daemons/Servicesminimum 0
38
Average RSS per Daemon (MB)minimum 0
18

Results

Estimated Total Daemon RSS (MB)
684.0
Running as % of Enabled
84.4%
Enabled but Not Running
7
Note
7 enabled daemons aren't currently running (may be one-shot/oneshot-type units, conditionally-started, or failed) — check with `systemctl list-units --all --state=inactive`.

Step by step

  1. 1Values used
  2. 2Estimated total daemon memory
  3. 3Estimated Total Daemon RSS (MB)= 684.0
  4. 4Running as % of Enabled= 84.4
  5. 5Enabled but Not Running= 7
  6. 6Note= 7 enabled daemons aren't currently running (may be one-shot/oneshot-type units, conditionally-started, or failed) — check with `systemctl list-units --all --state=inactive`.

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why would a service be 'enabled' but not currently 'active'?

Common reasons: it's a oneshot-type unit that runs once at boot and legitimately exits (RemainAfterExit=no), it's gated by a condition that isn't currently satisfied, it depends on a socket/timer and is only activated on demand (socket or timer activation), or it crashed/failed to start and hit its restart limit — `systemctl status <unit>` shows the specific reason.

How do I list all enabled services on a system?

`systemctl list-unit-files --state=enabled` lists every unit file configured to start at boot, while `systemctl list-units --type=service --state=running` shows what's actually active right now — comparing the two surfaces exactly which enabled services aren't currently running.

Is reducing the number of enabled daemons a good way to save resources?

It can help on memory-constrained systems or minimal container/VM images, but weigh it against functionality lost — disabling something like a logging daemon or security agent saves a modest amount of RAM at the cost of losing its function. Profile actual per-daemon RSS via `systemd-cgtop` or `ps` before deciding which are worth disabling.

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