Polder
A smart memory manager with one slider
Get it
If you've already added the repository, just run:
sudo apt install polder
First-time setup (add repository)
curl -fsSL -o /tmp/colaapps-archive-keyring.gpg \
https://colaapps.com/repo/colaapps-archive-keyring.gpg &&
sudo install -D -m 0644 /tmp/colaapps-archive-keyring.gpg \
/etc/apt/keyrings/colaapps-archive-keyring.gpg
sudo tee /etc/apt/sources.list.d/colaapps.list > /dev/null <<'EOF'
deb [signed-by=/etc/apt/keyrings/colaapps-archive-keyring.gpg] https://colaapps.com/repo stable main
EOF
sudo apt update
sudo apt install polder
The first two commands install the ColaApps signing key, so apt verifies every index it
downloads. Needs curl. Debian and Ubuntu.
Added ColaApps before, with [trusted=yes]? That turns
signature checking off — run the block above again, it overwrites the old line.
About
Polder
A smart memory manager with one slider: your machine stops killing itself over memory. Polder watches memory, forecasts when it will run out and, as far as you let it, tunes the kernel, creates and sizes swap, protects what must keep running, and steps in before the kernel's out-of-memory killer has to. It installs at Watch, which changes nothing. The window is a separate package, polder-desktop.
How much it does
| Stop | What Polder does |
|---|---|
| Off | Nothing, and safely undoes anything a higher stop did |
| Watch | Forecasts and warns before memory runs out. Changes nothing. The default after install |
| Advise | Watch, plus suggested fixes you can apply with one command |
| Tune | Sets swappiness and the reclaim watermark within your bounds |
| Provision | Tune, plus creates, grows and shrinks swap (zram and swapfiles) where you allow |
| Guard | Provision, plus protects sshd, the journal and the desktop; throttles, then pauses, a runaway. Never stops anything |
| Autopilot | Everything, choosing swap locations itself, and the last resort: if something has to give, Polder picks it by your rules, before the kernel's OOM killer would |
Install
Add the ColaApps APT repository (the APT tab above), then:
sudo apt install polder # the daemon and the polder command
sudo apt install polder-desktop # the window (Debian 13, Ubuntu 24.04 or later)
Use
polder # how the machine is, and what Polder is doing
sudo polder level tune # move the slider
sudo polder set swap.locations /data/swap
polder explain # what it did, and why
Requirements
Debian 12 or later, or Ubuntu 22.04 or later, on amd64 with systemd. The daemon is a static binary with no library dependencies.
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