This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revisionNext revisionBoth sides next revision | ||
fuss:linux [2020/02/07 21:03] – [Allow Binding Privileged Ports] office | fuss:linux [2020/05/12 23:36] – [Scraping a Site Automatically using SystemD] office | ||
---|---|---|---|
Line 1102: | Line 1102: | ||
will print the last wake-up type. | will print the last wake-up type. | ||
+ | ====== Issues with Stuck Cores ====== | ||
+ | It may happen that logs fill up with messages indicating that some power management policy cannot be enforced on a given CPU core: | ||
+ | < | ||
+ | cpufreqd: cpufreqd_loop | ||
+ | cpufreqd: cpufreqd_set_profile | ||
+ | </ | ||
+ | It may be that the CPU core is simply stuck and may need replugging. The following two commands will take the CPU offline and the next one will start the CPU back up: | ||
+ | <code bash> | ||
+ | echo " | ||
+ | echo " | ||
+ | </ | ||
+ | In doing so, the power management issue seems to be resolved. | ||
+ | ====== Automatically Add all RNDIS Devices to a Bridge ====== | ||
+ | Edit or create the file at ''/ | ||
+ | < | ||
+ | SUBSYSTEM==" | ||
+ | </ | ||
+ | where: | ||
+ | * '' | ||
+ | followed by the command: | ||
+ | <code bash> | ||
+ | udevadm control --reload | ||
+ | </ | ||
+ | to reload all udev rules. | ||
+ | |||
+ | The reason this works is due to '' | ||
+ | <code bash> | ||
+ | udevadm info -a / | ||
+ | </ | ||
+ | |||
+ | will show at the top the RNDIS device without any identifiers whereas the parent '' | ||
+ | |||
+ | One usage case for this rule is to connect a bunch of RNDIS devices to an USB hub and have them join the network automatically as they are hotplugged; for instance, Raspberry Pis [[fuss/ | ||
+ | |||
+ | ====== Scraping a Site Automatically using SystemD ====== | ||
+ | |||
+ | FTP sites can be scraped elegantly by using systemd and tmux on Linux. By starting a '' | ||
+ | |||
+ | The following script contains a few parameters underneath the '' | ||
+ | * the download path ('' | ||
+ | * the '' | ||
+ | * a descriptive name for the '' | ||
+ | |||
+ | <code bash> | ||
+ | [Unit] | ||
+ | Description=Scrape FTP Site | ||
+ | Requires=network.target local-fs.target remote-fs.target | ||
+ | After=network.target local-fs.target remote-fs.target | ||
+ | |||
+ | [Install] | ||
+ | WantedBy=multi-user.target | ||
+ | |||
+ | [Service] | ||
+ | # Configuration | ||
+ | Environment=DOWNLOAD_DIRECTORY="/ | ||
+ | Environment=DOWNLOAD_URL=" | ||
+ | Environment=TMUX_SESSION_NAME=" | ||
+ | # Internals | ||
+ | Type=oneshot | ||
+ | KillMode=none | ||
+ | User=root | ||
+ | ExecStartPre = -/bin/mkdir -p \"" | ||
+ | ExecStart=/ | ||
+ | ExecStop=/ | ||
+ | RemainAfterExit=yes | ||
+ | |||
+ | </ | ||
+ | |||
+ | The file should be placed under ''/ | ||
+ | |||
+ | Upon every reboot, the service file will create a detached tmux terminal and start scraping files from the URL. |