Which of the following is the main purpose of a parked CPU core?

Which of the following is the main purpose of a parked CPU core?

• Saves Power
• Increase performance of applications
• Reserves CPU core for specific application process
• To prolong the lifespan of the CPU 

 

EXPLANATION

This process essentially puts your CPU cores in a sleep state, and wakes them up when an application depends on higher core usage. Majority of the time this is left enabled unless your a power user or a gamer. It can increase performance slightly for those situations. On some processors, this option cannot be disabled.

SOURCE

https://ttcshelbyville.wordpress.com/2013/12/29/what-is-core-parking-and-should-you-adjust-it/

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In Vmware, what file extension does the disk descriptor file use?

In Vmware, what file extension does the disk descriptor file use?

• .vmtm
• .vmx
• .vmdk
• .vmdf 

EXPLANATION

The correct answer is .VMDK.
Two files can have this extension, the disk descriptor file and the flat vmdk file.
Source : https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&external...
Source : http://cdn.ttgtmedia.com/digitalguide/images/Misc/anatomy_avm_4.jpg

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What do you call the feature in packet-based data transmission protocols (Like TCP) that governs the amount of data (number of packets) the receiver is able to accept from the sender?

What do you call the feature in packet-based data transmission protocols (Like TCP) that governs the amount of data (number of packets) the receiver is able to accept from the sender?

• Sequence Number
• Jitter
• CiDR
• Sliding Window 

EXPLANATION

The sliding window feature informs the sender how much data (packets) the receiver can accept.  Since networks are dynamic and are prone to congestion this number fluctuates depending on a number of variables.  Essentially if my PC is sending a file to the server it may send 10 packets out of 20,000 to start the transfer.  If the server was able to receive all of those packets it may request more.
 This will continue until the server either can't accept more because its buffer is full or some packets were missed because of congestion.  The sender will then retransmit missed packets and begin to scale down the window until the server and the receiver are in sync.  This back and forth continues to the end of the transfer.
https://www.google.com/search?num=50&q=sliding+window+protocol&oq=Sliding+Window+pr&gs_l...

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What is cgroups in modern Linux kernels?

What is cgroups in modern Linux kernels?

• A set of tools for paravirtualization
• A feature that isolates and limits resource usage of processes
• A friendly IPtables manager written in C
• A collection of tools that prevents malware using mandatory access controls policies 

 

EXPLANATION

Cgroups (abbreviated from control groups) is a Linux kernel feature that limits, accounts for, and isolates the resource usage (CPU, memory, disk I/O, network, etc.) of a collection of processes.
If you are using Docker give it a try! This may be useful for hungry Java apps ;)
See more at Wikipedia and kernel.org

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What is the default TCP port used by Microsoft SQL server?

What is the default TCP port used by Microsoft SQL server?

• 1433
• 3389
• 1723
• 987

EXPLANATION

The default (and IANA official port) for Microsoft SQL Server is TCP 1433.
Port 3389 is the default port for Microsoft RDP.
Port 1723 is the default port for PPTP VPN.
Port 987 is used by the Companyweb sharepoint site on Microsoft Small Business Server 2008 and later.

SOURCE

https://msdn.microsoft.com/en-us/library/cc646023.aspx

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