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[rbdr/txt] / learning.md

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+2024-01-18: MacPPP with modem initialization options works much better than ZTerm + FreePPP, and allows 115200 baud. You just have to set the modem to initialize with AT, and then dial PPP.
+2024-01-17: Mastodon will NOT auto-clean the media directory, which can quickly bubble in size, and you can't ask sidekiq to deal with this so you need to set a cron job. A systemd.timer can handle both cases.
+2024-01-16: With dnsmasq + tailscale you can easily combine your home lab with a remote server and make management a lot easier without exposing some services to the web. A local dnsmasq running on raspberry pi can make sure all local services have a nice name, and then can point an internal url to the vps. In firewalld you need to block connections unless they come from your 100.0.0.0/8 block.
+2024-01-16: You don't actually need the users in unix in some situations, you can use an arbitrary number of the id and if the other system expects it, then it will work. In fact, you can "sudo" into that if runas_allow_unknown_id (then run sudo -u \#9999 <your_command>)

 2024-01-15: SELinux provides restrictions to files I wasn't aware of, and can prevent execution in some contexts. With eza you can view it with -Z.
 2024-01-14: On linux you can see logical volumes inside a partition with lsblk, they're shown as lvm. If you resize a partition, you still need to resize the lvm (eg. with `lvresize -l +100%FREE` to take all remaining free space), AND the filesystem (eg. using resize2fs). This is important eg when installing an OS from an image as you might not be using your whole disk.
 2024-01-14: On fedora rather than ufw or nftables, you use firewalld. You can create services (eg. gopher with port tcp 70 goes in /etc/firewalld/services/gopher.xml), attach them to zones with `firewall-cmd --zone=<YOURZONE> --add-service=gopher --permanent`
 2024-01-15: SELinux provides restrictions to files I wasn't aware of, and can prevent execution in some contexts. With eza you can view it with -Z.
 2024-01-14: On linux you can see logical volumes inside a partition with lsblk, they're shown as lvm. If you resize a partition, you still need to resize the lvm (eg. with `lvresize -l +100%FREE` to take all remaining free space), AND the filesystem (eg. using resize2fs). This is important eg when installing an OS from an image as you might not be using your whole disk.
 2024-01-14: On fedora rather than ufw or nftables, you use firewalld. You can create services (eg. gopher with port tcp 70 goes in /etc/firewalld/services/gopher.xml), attach them to zones with `firewall-cmd --zone=<YOURZONE> --add-service=gopher --permanent`