A Technical I.T./DevOps Blog
Problem scenario
To deal with lower back pain, your doctor advised you to deadlift. There is too much noise when you are deadlifting. The metal clankles loudly. How do you stop it?
Possible solution #1
Use silencer pads.
Possible solution #2
Wear ear plugs.
Possible solution #3
To prevent weights moving around and possibly being more quiet, use plastic clips to quiet the rattle.
Problem scenario
You want to stand for hours. You have a desk that allows you to type comfortably while standing. Sometimes your knees or feet hurt. What should you do?
Possible Solution
Try an anti-fatigue mat. It may make all the difference. You may want to wear sandals too.
Problem scenario
Some adjustable desks (with an electric motor) are much more affordable than others. Is something wrong with a cheap sit-to-stand desk?
Answer
Possibly. Verify how far down the table goes. Some models do not go down that far. Vivo makes a variety of desks, but some of their models do not go down very low when you are sitting compared to some other models. That may be a reason why you would not want to buy one. The table tops that are good for transport, and break down into different pieces, sometimes have seams; that is, the edge between the pieces when assembled will not make for a good writing surface. There are tradeoffs to different features. Transportation is a real concern. There is no getting around that.
You may want to view these sit-stand desks.
Try Coinrule.
This European company can allow you to buy crypto or learn more: Iconomi.com
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).
See also Shark Tank and this list.
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?
Solution
If there is a fire and someone is living above where firefighters can rescue someone, there could be a problem. People like to live on a high floor because of health reasons.
…residents living on lower floors are frequently exposed to high levels of exhaust from parking garages and street-level traffic. In contrast, residents on higher-level floors typically enjoy cleaner air.
https://www.6sqft.com/health-and-high-rise-living-is-higher-healthier/
The solution (to being a health-conscious prepper in a skyscraper in a big city) is to buy this backpack device (with a cable) and set it up well in advance; you may need to ask the landlord for permission.
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.
We have found some distributions of Linux have a configuration file for SSH that have "UsePAM yes" by default. According to the Linux Bible (page 618), most Linux distributions use PAM. Some applications use PAM -- not just SSH. PAM can add to the simplification and flexibility of security.
This Stackexchange posting gives mostly favorable encouragement toward using PAM.
For RHEL and Fedora, you probably should use PAM per this website posting.
It is not clear if you necessarily should. Many enterprises do use it, and many modern sources recommend it.
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, you could try Splunk or click on the link below corresponding to the web server technology you use (note that Nginx has two links):
Apache
IIS
Nginx:
Nginx.com
Loginradius.com (for Nginx)
WebSphere
Possible Solution #2 (workaround)
If the website when presented in a web browser (from the frontend) is all white, go here.
If the website when presented in a web browser (from the frontend) is all white and uses PHP, go here.
If the website is powered by GitLab, see this page.
Side note: If you want to configure Nginx to log in a JSON format, see this posting.
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, by Michael Kerrisk). Hardware supports the data-link layer of the TCP/IP protocol suite (this was taken from page 1181 of The Linux Programming Interface by Michael Kerrisk).
The Network Access Layer of TCP/IP model is supported by hardware (and not visible to users per Cisco's website).
With client-server interaction, the user interacts with a program (possibly a GUI app) in user space. Before the packets are sent from the local host, behind-the-scenes, the relevant TCP/IP packet transmission exists in kernel space. The packets are assembled on the remote server in its kernel space. Then the application in user space on the remote host would process the data or provide application services.