UNIX Desktop vs Server http linux vbird orglinuxbasic0110

UNIX 系統安裝 (Desktop vs Server) http: //linux. vbird. org/linux_basic/0110 whatislinux. php 2022/2/16 1

課程目標 (提醒…) • Unix as Desktop • Unix as Server 2022/2/16 4

Ubuntu 2022/2/16 5

Download required files • Virtual. Box – Google & Download • Ubuntu Desktop – Google & Download • Ubuntu Server – Google & Download

Ubuntu 版本之選擇… Server or Desktop? From: http: //www. serverwatch. com/tutorials/article. php/3715071 (OLD but still got some info …)

Desktop 與 Server 安裝後的差別？ 2022/2/16 9

Desktop 與 Server 安裝後的差別？ 2022/2/16 10

Server or Desktop? 只有介面的差異？ • http: //www. serverwatch. com/tutorials/article. php/ 3715071 (OLD but still got some info …) (過程省略, refer to the original post for details) • Two kernels with Ubuntu-server & desktop are compared – /boot/config-2. 6. 22 -14 -server – /boot/config-2. 6. 22 -14 -generic

Conclusions • Differences in – I/O Scheduler – Preemption – Memory – Ticks and HZ

I/O Scheduler - 1 • CFQ – tries to balance all read/write requests equally. • Deadline – gives a higher priority to read requests, and will re-order read/write requests aggressively to meet the goal of completing read requests within a specified time, without "starving" write requests, which are not given deadlines.

I/O Scheduler - 2 • Anticipatory – aims to reduce latency by giving priority to already-running applications. It is supposed to be suitable for smaller systems with one or two hard disks, and single or dual-core CPUs. • NOOP – is a minimal scheduler for systems with hardware that handles I/O scheduling, like large SCSI RAID arrays.

Which for which? • Ubuntu makes CFQ the default for desktop kernels • Deadline for server kernels. • The goal is the same for all of them: to optimize hard disk bandwidth for different classes of workloads.

Preemption • Preemption works along with scheduling to fine-tune … – Performance – Efficiency – Responsiveness.

Non-preemptive • Non-preemptive multitasking is a style of computer multitasking in which the operating system never initiates a context switch from a running process to another process.

Preemptive • Preemptive multitasking involves the use of an interrupt mechanism which suspends the currently executing process and invokes a scheduler to determine which process should execute next.

Preemption • The server kernel has kernel preemption turned off • The desktop kernel has it enabled

Desktop : Preemption ON • For desktop systems users typically have several things going at once: writing documents, playing music, Web surfing, downloading and so on. • Users don't care how responsive background applications are; they care only about the ones they're actively using. – So if loading a Web page takes a little longer while the user is writing an e-mail, it's an acceptable trade-off. – Overall efficiency and performance are actually reduced but not in a way that annoys the user.

Server : Preemption OFF • On servers you want to minimize any and all performance hits, so turning off preemption is usually the best practice.

Memory • The 32 -bit server kernel supports up to 64 GB of memory; • The desktop kernel, a mere 4 GB • You'll only see these options in 32 -bit kernels because the 32 -bit address space is big enough to support only 4 GB without trickery

Memory • On a 64 -bit system you won't see any memory options because it doesn't need hacks to overcome a lack of memory addressing space – You should be fine until your needs exceed 16 60 exabytes (2 ) of RAM.

Ticks and HZ • Server : 100 Hz – The server kernel looks up and peers around 100 times per second for something to do. • Desktop : 250 Hz – The desktop kernel looks up and peers around 250 times per second for something to do

Ticks and HZ • Lower ticks/Hz numbers equal lower overhead and higher latency • Higher numbers equal higher overhead and lower latency. – generally mean the system feels more responsive, at the price of higher CPU usage. – Some processes require more interrupts; for example, video processing and Vo. IP servers need 1000 Hz.

i 386 or AMD 64？

Ubuntu Desktop Installation • Virtual. Box 設定 • 安裝 2022/2/16 28

Virtual. Box 設定 (Desktop) 2022/2/16 29

Virtual. Box 設定 (Desktop) 2022/2/16 31

Virtual. Box 設定 (Desktop) 2022/2/16 32

Virtual. Box 設定 (Server) 2022/2/16 33

Types of Network (Virtual. Box)

NAT http: //download. ithome. com. tw/article/index/id/996

橋接 (Bridged) http: //download. ithome. com. tw/article/index/id/996

內部網路 (Internal Network) 主機 (host) 抓不到內部虛擬機 (guests) 的通訊 http: //download. ithome. com. tw/article/index/id/996

NAT 網路 (NAT Services) 類似在 Internal network 裡建構一個具 NAT 的環境 Each virtual machine guest configured for the same NAT Networking network can see the other guests configured to be on that network. http: //download. ithome. com. tw/article/index/id/996

僅限主機 (Host only) • Used to create a network containing the host and a set of virtual machines, without the need for the host's physical network interface. • Instead, a virtual network interface (similar to a loopback interface) is created on the host, providing connectivity among virtual machines and the host.

開始安裝 Desktop … (Your Turn)