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Showing posts with label linux admin. Show all posts
Showing posts with label linux admin. Show all posts

Friday, May 10, 2019

Linux SysAdmin] 2. What is a server?

People who are interested in server hardware maybe have thought about it once. 'What is a server?' A server is a device or software that provides a service. 

For example, you might be using a Wi-Fi router at home. When you get home, your smartphone will automatically get an IP address from it and you will use the Internet through it. So what service does the Wi-Fi router provide for your smartphone? 

It is a DHCP service. The Wi-Fi Router acts as a DHCP server and your smartphone as a DHCP client. In other words, the DHCP server software is installed on your Wi-Fi router and the DHCP client software is installed on your smartphone. A client is a device or software that accesses a service provided by a server. 

In general, when people hear the server, they will think of the following hardware:


But a device that provides a service can be called a server.

What is different between a server and a desktop?

Anyway, let's take a look at the server. How is it different from the desktop you use at home?

The first is a price difference. The server is more expensive than the desktop. In general, servers use larger and more expensive components than desktop. For Example, the following kinds of CPU are installed within the x86 desktop and the x86 server.

Desktop
x86 Server
 - Intel Core X Processor
 - AMD Ryzen Processor
 - Intel Xeon E Processor
 - AMD EPYC Processors


What companies are the x86 server manufacturer? HP, Dell, Fujitsu, Lenovo, Gigabyte, ASUS, Tyan, Supermicro and so on. Examples of Unix server CPUs are IBM Power CPU and Oracle SPARC CPU. Have you ever thought about how expensive a server CPU would be?



The second is performance. The desktop usually uses a single CPU. But the server can use multiple CPUs. The Intel Xeon E5 product support two and four-socket systems. And The Intel Xeon E7 product support from two to eight sockets. Unix processor product support up to dozens of sockets systems.

How much memory supported per CPU?

Intel Core i9
Intel Xeon Platinum 9282
AMD EPYC 7601
 128GB
 2TB
 2TB

How many cores supported per CPU?

Intel Core i9
Intel Xeon Platinum 9282
AMD EPYC 7601
 16
 56
 32

How peaceful will be the programs running on a system with 4TB memory? I would like to use such a system. :D

The third is the availability. You will turn off your desktop when work is finish, but the server should be stable 24/7. Servers are designed to provide reliable services in a mission-critical enterprise environment and are typically installed and operating in a data center. Stable power supply, optimum temperature, and humidity maintenance, the dust-free environment is very important.


Certain parts of the server are modular and are designed to be easily replaceable if they fail. Also, it has a fault-tolerant structure. For example, the power supply has an N + 1 structure. So even if one power supply fails, the server service goes back to normal.

The fourth is scalability. After the server is installed, it is likely that the service will gradually increase over time. Depending on the service load, CPU power may be needed more and there may be insufficient memory size for applications or storage capacity for data. At the point, the server should be able to be scalable enough for the resources you need.


For example, suppose you installed an FC HBA card on a server and then connected it to a SAN network and allocated a certain amount of external storage space for storing data. When storage space runs out at some point over time, it must be able to increase external storage capacity and allocate additional space to servers without rebooting.

So far, you've looked at the features of the server.

I am not familiar with English yet and I don't know if it was explained well. It will improve gradually. So see you next post. Thank you.



Tuesday, May 7, 2019

Linux SysAdmin] 1. Starting Linux SysAdmin

Hello, guys. Over the next few weeks, I will post how to manage Linux. Linux is one of the operating systems installed and operated on many servers. There are various Linux operating systems such as Red Hat Enterprise Linux, SUSE Linux Enterprise Server, Fedora, CentOS, Ubuntu and so on. Among these operating systems, I will post about how to manage CentOS and Ubuntu.


Linux is installed and running on a wide variety of hardware and maybe you see servers with an Intel or AMD CPU(s). The above picture is Fujitsu PRIMERGY RX300 S8 server with dual Intel Xeon E5 CPU. We bought this server 4 years ago and it is still working without any problem. I installed Ubuntu Linux at that time and it is still in good use. You can see what the inside of the server looks like from the photo above. Middle or high-end servers are more complex.

Using a physical server for personal learning is costly. Because it costs thousands to tens of thousands of dollars per server. If you want to test the network, you need several servers. So how much money do you need for the test?

Don't worry. With virtualization technology, you can create and use multiple virtual machines on your computer. So I posted several posts about VMware Workstation Pro. It is hosted hypervisor to do intuitive and easy to use. The disadvantage is that it is commercial software. But it will be cheaper than the value of technology that can be acquired through it.

If you don't know how to use VMware Workstation Pro, please refer the following post.

https://sunguruitchannel01.blogspot.com/2013/12/categories-quick-link.html

In the next post, you will know what the server is.

See you next. Thank you.