CompTIA SK0-005 Practice Test - Questions Answers, Page 30

Separate circuits and multiple UPSs can provide fail-safe power redundancy for a server rack. Separate circuits mean that the server rack is connected to two or more independent power sources, such as different utility lines or generators. This can prevent a single point of failure in the power supply, as if one circuit goes down, the other circuit can still provide power to the server rack1. Multiple UPSs mean that the server rack has two or more uninterruptible power supplies, which are devices that provide backup power and surge protection in case of a power outage or fluctuation. Multiple UPSs can be connected to separate circuits, or to different outlets on the same circuit, to increase the reliability and availability of power for the server rack23.

A single-threaded application is an application that can only execute one task or process at a time. A single-threaded application can only utilize one CPU core, regardless of how many cores are available or assigned to the virtual machine. Therefore, adding more vCPU cores to the VM will not improve the performance of the application, as it will still be limited by the speed and capacity of one core12. To troubleshoot this issue, the administrator should check if the application is single-threaded or multi-threaded. This can be done by using tools such as Task Manager, Performance Monitor, or Process Explorer on Windows, or top, htop, or ps on Linux34. If the application is single-threaded, the administrator should consider the following options:

Reduce the number of vCPU cores on the VM to match the number of threads that the application can use. This can help avoid CPU contention and co-stop issues that may arise from having too many vCPUs relative to the number of physical cores on the host5.

Upgrade the physical CPU on the host to a faster or newer model that can provide higher clock speed and performance for the single core that the application uses.

Optimize the application code or configuration to make it more efficient or multi-threaded, if possible. This can help the application take advantage of multiple cores and improve its performance.

SCP (Secure Copy Protocol) is a protocol that allows users to securely transfer files between servers using SSH (Secure Shell) encryption. SCP encrypts both the data and the authentication information, preventing unauthorized access, interception, or modification of the files1. SCP also preserves the file attributes, such as permissions, timestamps, and ownership2.

The BIOS (Basic Input/Output System) or UEFI (Unified Extensible Firmware Interface) setup is a program that allows users to configure the hardware settings of a computer, such as the CPU, memory, disk, and boot options. The BIOS/UEFI setup can be accessed by pressing a specific key (such as F2, F10, or Delete) during the boot process, before the operating system loads12.

One of the settings that can be changed in the BIOS/UEFI setup is the CPU hyperthreading option.

Hyperthreading is a technology that enables a single physical CPU core to execute two threads or tasks simultaneously, improving the performance and efficiency of multi-threaded applications. However, some software licenses may limit the number of CPU cores or threads that can be used, and therefore require disabling hyperthreading on the server34.

To disable hyperthreading on a server, the administrator will likely need to enter the BIOS/UEFI setup and navigate to the processor options menu. There, the administrator will find a setting for Intel о Hyperthreading Technology or Hyperthreading Function, which can be enabled or disabled. The administrator will need to disable this setting and save the changes. This will turn off hyperthreading on the server and reduce the number of logical CPUs to match the number of physical cores5.

Cloud IaaS (Infrastructure as a Service) is a service model that allows users to rent virtualized computing resources over the internet, such as servers, storage, network, and software. Cloud IaaS can provide several benefits for disaster recovery and failover scenarios, such as:

Lower cost: Cloud IaaS can reduce the capital and operational expenses of building and maintaining a physical disaster recovery site, as users only pay for the resources they use on demand12.

Scalability: Cloud IaaS can offer flexible and elastic scalability of resources, as users can easily provision or deprovision resources according to their needs and workload12.

Availability: Cloud IaaS can ensure high availability and reliability of the application, as users can leverage the cloud provider's redundant and geographically distributed infrastructure12.

Simplicity: Cloud IaaS can simplify the failover process, as users can use the cloud provider's tools and services to automate and orchestrate the failover operations12.

Therefore, building a cloud IaaS and performing a failover of the application would be the most costeffective solution for the company, as it would allow them to simulate a failover of a critical application on production configurations and IP address schemes without investing in a physical disaster recovery site.

RAID 5 is a RAID level that uses disk striping with parity. It requires a minimum of three disks and can handle one disk failure. RAID 5 distributes the parity information across all the disks in the array, which improves the read performance and reduces the write penalty. The capacity of a RAID 5 array is (N-1) times the size of the smallest disk, where N is the number of disks in the array. Therefore, for six 4TB disks, the capacity of a RAID 5 array would be (6-1) x 4TB = 20TB, which meets the minimum disk space requirement of 19TB. RAID 5 also has the least amount of disk space lost to RAID overhead among the options, as it only uses one disk's worth of space for parity

An incremental backup is a backup method that only backs up the files that have changed since the last backup, whether it was a full or an incremental backup. An incremental backup can save disk space and time, as it only copies the new or modified data. An incremental backup can also improve the RTO (Recovery Time Objective), which is the maximum acceptable time to restore data after a disaster. This is because an incremental backup can restore data faster than a full or a differential backup, as it only needs to apply the latest changes to the previous backup1.

The user has likely fallen victim to a phishing scam, which is a fraudulent attempt to obtain sensitive information, such as passwords, by disguising as a legitimate entity. The link in the email that required the user to change the account password was probably a fake website that mimicked the company's external database, and captured the user's credentials when they entered them. This could compromise the security and integrity of the company's data, as well as the user's identity and privacy12.

The company should take immediate action to prevent further damage and investigate the incident. The first step is to disable the user's account and inform the security team. Disabling the user's account can prevent unauthorized access to the external database by the attackers, who may use the stolen credentials to log in and manipulate or steal dat a. Informing the security team can alert them of the breach and allow them to take appropriate measures, such as scanning for malware, changing passwords, notifying other users, and reporting the incident34.

A differential backup is a backup method that protects all the changes that have occurred since the last full backup. A differential backup copies all the files that have been added or modified since the last full backup, regardless of whether they have been backed up before or not. A differential backup does not reset the archive bit of the files, which means they will be backed up again in the next differential backup. A differential backup requires more storage space and time than an incremental backup, but it simplifies the restoration process, as only the last full backup and the last differential backup are needed to restore the data