If a server has two arrays on the failed server: a two-drive RAID 0 set for the OS, and an eight-drive RAID 10 set for data, then the most likely failure scenario that caused the server to crash and not boot is that a drive failed in the OS array. RAID 0 is a RAID configuration that stripes data across two or more drives without parity or redundancy. RAID 0 offers high performance but no fault tolerance. If one drive fails in RAID 0, all data is lost and the system cannot boot. RAID 10 is a RAID configuration that combines disk mirroring and disk striping with parity. RAID 10 offers high performance and fault tolerance. RAID 10 can tolerate up to one drive failure per mirrored pair without losing data or functionality. References:
https://www.technewstoday.com/what-is-a-raid-0/ https://www.technewstoday.com/what-is-a-raid-10/

Explanation
To ensure the partition is available to the OS, the technician must verify that the volume is formatted as GPT.
GPT (GUID Partition Table) is a partitioning scheme that defines how data is organized on a hard disk drive (HDD) or a solid state drive (SSD). GPT uses globally unique identifiers (GUIDs) to identify partitions and supports up to 128 primary partitions per disk. GPT also supports disks larger than 2 TB and has a backup copy of the partition table at the end of the disk for data recovery. GPT is required for installing Windows on UEFI-based PCs, which offer faster boot time and better security than legacy BIOS-based PCs.

Explanation
A warm site is a type of disaster recovery site that has a target storage array that receives replication traffic and servers that are only powered on in the event of a disaster. A warm site is a compromise between a hot site and a cold site. A warm site has some equipment and data ready, but requires some configuration and restoration before resuming operations. A warm site is usually located in a different geographic area than the primary site and has redundant power, cooling, network, and security systems. A warm site is suitable for organizations that can tolerate some downtime and data loss in case of a disaster. A cloud site is a type of disaster recovery site that uses cloud-based resources and platforms to store backups and restore data and applications after a disaster. A cold site is a type of disaster recovery site that has only basic infrastructure and space available, but requires significant setup and installation before resuming operations. A hot site is a type of disaster recovery site that has all the equipment and data ready to resume operations as soon as possible after a disaster.
References: https://www.techopedia.com/definition/11172/hot-site
https://www.techopedia.com/definition/11173/warm-site
https://www.techopedia.com/definition/11174/cold-sitehttps://www.techopedia.com/definition/29836/cloud-reco

A misconfigured hosts file can cause name resolution issues on a server. A hosts file is a text file that maps hostnames to IP addresses on a local system. It can be used to override DNS settings or provide custom name resolution for testing purposes. However, if the hosts file contains incorrect or outdated entries, it can prevent the system from resolving hostnames properly and cause connectivity problems. To fix this issue, the administrator should check and edit the hosts file accordingly.

Disk Management displays whether a disk is online (available), or offline.
In Windows, by default, all newly-discovered disks are brought online with read and write access.
In Windows Server, by default, newly-discovered disks are brought online with read and write access unless they are on a shared bus (such as SCSI, iSCSI, Serial Attached SCSI, or Fibre Channel). Disks on a shared bus are offline the first time they are detected.
You would first need to bring online (available) then choose the partition and during this choose simple or spanned... etc. BCD are just options that you can choose later.
https://learn.microsoft.com/en-us/windows-server/storage/disk-management/manage-disks