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root is the superuser account on the system — it (basically) has all privileges. Many systems are configured so that you can use the sudo command in front of another command to run that command "as root" — that is, as if you are the root user, with the same privileges. It is usually the case that you need root privileges to install system packages, which is ...


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What does “are you root?” mean? In order to install packages systemwide (what apt-get does), it needs root privileges, since you will be creating and changing system files (root is the usual name for the *nix administrator account). The «are you root?» message is a gentle reminder that you "need to be root" in order to run apt-get install. This is the most ...


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You need root privileges in order to execute system updates via apt-get. You can switch to a root account using su root. It appears that you do not have the sudo program installed.


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When running sudo ls > /root/out.txt only the ls part of the command is being run with elevated privileges. Because of this the redirection part of your command does not have the permissions needed to the location you want. Instead you can use tee prefixed with sudo like so: ls | sudo tee /root/out.txt


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Google Compute Engine allows you to provision a Linux VM in your chosen region which you can then ssh into with root privileges. It's cheap and you can get $300 worth of usage as a free trial.


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sudo su asks for the user's password, the user has to be in the sudo/adm/admin/wheel group (depening on flavour of the OS) to be able to execute sudo. The root password will be prompted when using su alone. Check the settings in /etc/sudoers file to see why you are not being asked for a password while using sudo. Most likely the time-out is set to a few ...


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Running su invokes bash in non-login mode. Bash then reads .bashrc to configure its environment. Runing su - invokes bash as a login shell. In this mode /etc/profile is executed if it exists. Bash also searches for ~/.bash_profile, ~/.bash_login and ~/.profile executing the first file it finds. Although not documented, it appears to execute ~/.bashrc ...


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I realized that I forgot to mention that I aborted cp -a after checking the destination in another terminal as I was copying 300+ gb of data. Thanks to Gilles' comment I started testing to see whether it only happens to directories or not. As the tests prove below, basically all files are written as root and the old attributes are applied to the ...


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Systemd is working with services and targets. Targets is the equivalent of runlevels, services is the equivalent of init scripts. Most of systemd configuration is located in /usr/lib/systemd, while standard init are in /etc/{init.d,rc*.d,inittab}. When an issue kicks in during the boot process (default are getty.target or graphical.target, you can get them ...


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Low-level control of USB devices is done via /dev/bus/usb, and you need to set the right permissions on the device there. The way to do that is with a udev rule: Create a file (such as /etc/udev/rules.d/52_local-usbtiny.rules) with: SUBSYSTEM=="usb", ATTR{idVendor}=="1781", ATTR{idProduct}=="0c9f", MODE="664", GROUP="plugdev" That sets the group to ...


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A free account at SageMath Cloud may fit your purpose. My account allows me to upload/download programs and compile/run them on a Ubuntu box located in the USA. The purpose of SageMath.org is to provide free, open source math software. The website is based on Python, but Python is not the only programming language available. In particular, an interactive ...


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At several points in rc.sysinit, rcS-emergency will be run when there's a problem requiring administrator intervention, such as: echo $"*** An error occurred during the file system check." echo $"*** Dropping you to a shell; the system will reboot" echo $"*** when you leave the shell." str=$"(Repair filesystem)" PS1="$str \# # "; export PS1 [ ...


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That looks very odd to me - what you described is definitely not a known issue. I've used cp -a extensively (including to clone entire Linux systems) and the only time I've seen a problem, it was caused by a bug in XFS (which was later fixed). My guess is that it's a bug in btrfs, which is still undergoing extensive development. Is it reproducible? Can you ...



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