> ## Documentation Index > Fetch the complete documentation index at: https://sysg.dev/llms.txt > Use this file to discover all available pages before exploring further. # logs # logs View stored output from managed services. ```sh theme={null} $ sysg logs ``` > **Info:** From the interactive `sysg status` table, select a UNIT with > Tab/arrow navigation and press **L** to jump straight into that unit's logs. > The status shortcut runs `sysg logs -s -l 100 --stream 2`, which shows > the latest 100 lines and refreshes the snapshot every 2 seconds. ## Options | Short | Long | Description | | ----- | ------------- | -------------------------------------------------------------------------------------------------- | | `-c` | `--config` | Path to configuration file | | `-` | `--purge` | Reset log files instead of displaying them | | `-` | `--prune` | Delete rotated log backups instead of displaying logs (requires `--max-size` and/or `--max-age`) | | `-` | `--max-size` | When pruning, cap total rotated-backup size (e.g. `500MB`, `2g`) | | `-` | `--max-age` | When pruning, remove rotated backups older than this (e.g. `7d`, `12h`) | | `-s` | `--service` | The name of the service whose logs should be displayed (optional) | | `-p` | `--project` | Filter logs by stable project id | | `-l` | `--lines` | Number of lines to show (default: 50) | | `-k` | `--kind` | Kind of logs to show: stdout, stderr, or supervisor. Omit this flag to show stdout+stderr together | | `-` | `--stream` | Continuously refresh the latest log snapshot at the provided interval (e.g., `5`, `1s`, `2m`) | | `-` | `--sys` | Opt into privileged system mode. Requires running as root | | `-` | `--log-level` | Set verbosity (`debug`, `info`, `warn`, `error`) | ## Examples ### View recent logs from all services ```sh theme={null} $ sysg logs ``` ### View logs from specific service ```sh theme={null} $ sysg logs --service api ``` To disambiguate a service in a multi-project supervisor, provide the stable project id: ```sh theme={null} $ sysg logs --project arbitration --service api ``` > **Info:** By default, `sysg logs` shows a stacked stdout+stderr stream in > capture order. systemg adds its own UTC capture timestamp and stream label to > service output as it is written, then reads the combined service log for the > default view. Use `--kind stdout` or `--kind stderr` when you need a single > stream only. ### Purge logs for a specific service ```sh theme={null} $ sysg logs --service api --purge ``` This truncates `api`'s current `stdout` and `stderr` log files in place and does not print logs. ### Purge logs for all services ```sh theme={null} $ sysg logs --purge ``` This truncates all service log files, plus `supervisor.log`, in place and does not print logs. ### View stderr logs ```sh theme={null} $ sysg logs --service api --kind stderr ``` ### View supervisor logs ```sh theme={null} $ sysg logs --kind supervisor ``` ### Show more history ```sh theme={null} $ sysg logs --service api --lines 200 ``` ### Stream snapshots ```sh theme={null} $ sysg logs --service api --lines 200 --stream 2 ``` In stream mode, each refresh prints a new snapshot of the latest `--lines` entries. ### Prune rotated backups ```sh theme={null} $ sysg logs --prune --max-size 500MB --max-age 7d ``` Deletes rotated backup files (`{name}.log.1`, `{name}.log.2`, …) older than `--max-age` and then trims the remaining backups oldest-first until their total size is under `--max-size`. Active `.log` files are never touched. At least one of `--max-size` or `--max-age` is required. ## Log files Logs are stored in `~/.local/share/systemg/logs/`: * `{service}.log` - Canonical stdout+stderr stream in capture order * `{service}_stdout.log` / `{service}_stderr.log` - Legacy split-stream files from older systemg versions, still read as a fallback when no canonical log exists * `supervisor.log` - systemg's own log output ### Rotation and retention Every active log file (service logs and `supervisor.log`) is size-capped. When an active file would exceed `logs.max_bytes` (default 10 MiB) it is rotated to `{name}.log.1`, older backups shift up, and at most `logs.max_files` (default 5) numbered backups are retained. A single log event larger than 16 KiB is truncated with a `…[truncated N bytes]` marker before it is written, so one oversized payload cannot blow past the size cap. Tune the caps with the `logs.max_bytes` / `logs.max_files` config keys, globally or per service. systemg's own verbosity is `info` by default and honors per-crate `RUST_LOG` directives (for example `RUST_LOG=mycrate=debug,noisycrate=warn`), so enabling debug for one target does not pull in dependency-wide debug noise. Each captured service line is stored with a systemg capture timestamp and stream label: ```text theme={null} 2026-05-14T02:05:13.470911Z stderr Compiling tungstenite v0.28.0 2026-05-14T02:05:13.471020Z stdout request completed status=200 ``` ## Performance model For the default `file` logging sink, systemg captures each service's stdout and stderr through pipes and writes both streams through one per-service writer into `{service}.log`. On Linux and macOS, the default `sysg logs` view tails that file directly with `tail -F` in follow mode. `--kind stdout` and `--kind stderr` filter recent captured lines by the stored stream label. The command itself is lightweight; the continuous cost comes from the capture threads, one writer thread, and one append-only file write path per service. For high-output production workloads, configure `logs.sink: none` globally or per service to discard service output and avoid systemg log-writer threads, pipe backpressure from log capture, and file growth. ## See also * [`status`](/how-it-works/commands/status) - Check service health * [`inspect`](/how-it-works/commands/inspect) - View detailed metrics