This European company can allow you to buy crypto or learn more: Iconomi.com
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Problem scenario
You want to watch a movie to help brainstorm the invention of a new product. You want to come up with a useful invention that you can potentially monetize. What should you do?
Solution
We do not know of a movie that can do this, but you may want to buy Invention USA (either season 1 or season 2 or individual episodes of those seasons).
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Continue reading “What Show Can Help You Invent a Profitable Product?”
Problem scenario
You want to prepare for the potential situation where you need to escape from a skyscraper. You do not want to depend on the stairs or elevator being accessible. You do not think that going to the roof for a helicopter landing would help you. What should you do if you live above the 7th or 10th floor and the firefighters cannot get a ladder to your apartment?
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Continue reading “How Do You Escape from a High Rise when the Fire Department Cannot Rescue You?”
Problem scenario
You use Linux and want to configure SSH. Should PAM be enabled in your /etc/sshd/confifig file?
Answer
Maybe. This heavily-voted up answer on StackExchange says to not use PAM.
This external page says that it is turned off by default.
This source says PAM is (or was because it is from 2011) not desirable.
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Problem scenario
You have a website that is not working. You tried using Fiddler on the front-end. You want to examine the logs on the backend to find the problem. What should you do?
Possible Solution #1
Use a case insensitive grep for “error” or “violation”. Search also for patterns such as “40” and “50” in separate searches.
To get help finding the logs,
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Continue reading “How Do You Search the Logs of a Website that Is Not Functioning Properly?”
Question
Networking is usually very important for a Linux/Unix OS. For typical applications that use networking, do kernel space or user space play a role?
Answer
Yes, both play a role.
User space facilitates the application layer of the TCP/IP protocol suite; kernel space facilitates the network and transport layers of the TCP/IP protocol suite (this was taken from page 1181 of The Linux Programming Interface,
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Continue reading “Do Either Kernel Space or User Space Play a Role in Operating Systems Networking?”
Problem scenario
You have no new physical disks, but you want to partition an existing Linux system. What do you do to benefit from logical partitions on an existing Linux machine?
Solution (with important warning)
WARNING: THIS CAN MAKE YOUR LINUX MACHINE UNBOOTABLE.
DON’T DO IT UNLESS YOU KNOW WHAT YOU ARE DOING.
(The solution below was influenced by this external site.)
sudo fdisk -l
You should see something like this:
Device Start End Sectors Size Type
/dev/sdc4 2048 4095 2048 1M BIOS boot
/dev/sdc5 4096 2101247 2097152 1G Linux filesystem
/dev/sdc6 2101248 20969471 18868224 9G Linux filesystem
Run this:
sudo fdisk /dev/sdc6
Respond to the prompts: n for new.
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Continue reading “Without Adding New Storage Capacity, How Do You Create a Partition?”
Problem scenario
You want to see what the max file size space consumption limits are for different users and groups on your Linux system. You only are interested in the quota-imposed limits. What command do you run to see the limits?
Solution
Run this:
sudo repquota -a …
Continue reading “How Do You Know what Your File, User, or Group Max Limits Are?”
Problem scenario
You get an error message when you run openvpn. You are trying to start the client service. You get “insufficient key material or header text not found in file”. What should you do?
Possible Solution #1
Backup your client.conf file.
Find your tls-crypt.key file. If you have none, run this:
openvpn –genkey –secret /etc/openvpn/tls-crypt.key
Copy every line in the tls-crypt.key file and paste it into a particular location of the client.conf file.
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Problem scenario
You have seen Linux distributions use wheel whereas some use admin. What is the difference?
Solution
For most purposes, there is no difference.
Many RedHat distributions use wheel (per page 429 of Fedora and RedHat by Sobell).
Ubuntu uses wheel (per this posting).
To add a Linux user to a sudoers file,
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Continue reading “What Is the Difference between the wheel Group and the admin Group?”