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Claudio c9eb7fdab3 118-elementsynapse: document disk-full fix + bridges

Rootfs grew to 16 GiB on 2026-05-15. Added bridges section
(mautrix slack/signal/meta/linkedin/whatsapp), synapse-admin
port, Postgres backend note, and operational tips for future
disk growth.

2026-05-15 21:48:58 +02:00

3.4 KiB

Raw Blame History

118 — `elementsynapse`

Matrix homeserver (Synapse). Backs @dtoro:avispero and @claudio:avispero.

At a glance

Hostname: elementsynapse
IP: 192.168.8.239
Privilege: unprivileged
Resources: 1 core / 2 GiB RAM / 16 GiB rootfs (grown from 8 GiB on 2026-05-15 after disk-full incident)
Mounts: none from /mnt/library
Public hostname: matrix.hubris.network → caddy → :8008
server_name: avispero (intentionally different from the public URL).
Database: PostgreSQL on 127.0.0.1:5432 (the homeserver.db SQLite file in /var/lib/matrix-synapse/ is a leftover, not in use).

Service / port map

Service	Listen	Notes
synapse	`:8008`	Matrix client-server / federation HTTP. Caddy terminates TLS for `matrix.hubris.network`.
synapse-admin	`:5173`	Web UI (vite dev server) for Synapse admin API.
mautrix-whatsapp	`:29318`	Docker, `network_mode: host`, compose in `/root/mautrix-whatsapp/`.
mautrix-meta	`127.0.0.1:29319`	Facebook/Instagram bridge, `/root/mautrix-meta/`.
mautrix-signal	`127.0.0.1:29328`	`/root/mautrix-signal/`.
mautrix-slack	`127.0.0.1:29335`	`/root/mautrix-slack/`.
mautrix-linkedin	`127.0.0.1:29341`	`/root/mautrix-linkedin/`.

Bridges (mautrix)

All five bridges run as plain docker compose stacks under /root/mautrix-<name>/ — no systemd unit, restart: unless-stopped. Their appservice registration YAMLs live in /etc/matrix-synapse/ and are listed in homeserver.yaml under app_service_config_files. If a bridge daemon is down, Synapse logs push_bulk … ConnectionRefusedError and retries every 512 s; restart the bridge with cd /root/mautrix-<name> && docker compose up -d.

Operational notes

Rootfs is on pve LVM-thin, grow with pct resize 118 rootfs +<N>G from the host — resize2fs runs automatically.
/var/lib/matrix-synapse/media_store is the dominant grower (~2 GiB at last check). If disk pressure returns, purge remote media via the Synapse admin API before resizing further.

Known issues

~~Disk usage was 86.8% at last claudio-monitor reading on 2026-04-21~~ — resolved by growing rootfs to 16 GiB on 2026-05-15.

claudio-bot (123) — connects directly to 192.168.8.239:8008 (avoids hairpin-NAT TLS issue on the public URL)
Caddy
DNS
Monitoring

Changelog

2026-05-15 — disk-full incident, rootfs grown to 16 GiB, bridges restarted

Element/Synapse was unreliable for ~2 days: messages dropping, sync requests stalling, mautrix bridges (slack/signal/meta/linkedin/whatsapp) all exited around 2026-05-13. Root cause: rootfs reached 100% (19 MB free of 7.8 G); Synapse logs showed OSError: [Errno 28] No space left on device during flush. Fix: pct resize 118 rootfs +8G (host pve VG had plenty of headroom), journalctl --vacuum-size=50M to recover ~200 M, systemctl restart matrix-synapse, then docker compose up -d in each /root/mautrix-* directory. Also expanded this wiki page to document the bridges, synapse-admin, and the actual DB backend (Postgres, not the SQLite leftover).

2026-04-28 — wiki entry created

Initial documentation.

3.4 KiB Raw Blame History

118 — elementsynapse