You are an Enterprise administrator for contoso.com. All the servers in the domain run Windows Server 2008 and all client computers run Windows Vista.
The network contains a Microsoft SQL Server 2005 that has two RAID 1 arrays and one RAID 5 array configured.
You have been assigned the task to allocate hard disk space on the server and ensure maximum performance of the SQL Server application and minimum loss of write performance if a hard disk drive fails. You also need to prevent the loss of data if a single hard disk drive fails.
Which of the following options would you choose to achieve the desired goal?
A.
Use RAID 1 arrays to place OS files and SQL database files and RAID 5 array to place SQL transaction logs
B.
Use RAID 5 array to place types of files.
C.
Use RAID 1 arrays to place OS files and SQL transaction logs and RAID 5 array to place SQL database files
D.
Use RAID 5 arrays to place OS files and RAID 5 array to place SQL transaction logs and SQL database files.
E.
None of the above
Explanation:
To allocate hard disk space on the server and meet other requirements, you need to place the operating system files on one of the RAID 1 arrays. Place the SQL transaction logs on the other RAID 1 array and place the SQL database files on the RAID 5 array.
RAID version 1 was the first real implementation of RAID. It provides a simple form of redundancy for data through a process called mirroring. This form typically requires two individual drives of similar capacity. One drive is the active drive and the secondary drive is the mirror. When data is written to the active drive, the same data is written to the mirror drive.
This provides a full level of redundancy for the data on the system. If one of the drives fails, the other drive still has all the data that existed in the system. It is best to place OS files because it provides full redundancy of data. It does not increase performance therefore it is not fit to store SQL database files.
For SQL database files you should use RAID 5 array because it is the most powerful form of RAID that can be found in a desktop computer system. This method uses a form of striping with parity to maintain data redundancy. The parity bit shifts between the drives to increase the performance and reliability of the data. The drive array will still have increased performance over a single drive because the multiple drives can write the data faster than a single drive. The data is also fully redundant because of the parity bits. In the case of drive 2 failing, the data can be rebuilt based on the data and parity bits on the two remaining drives. Data capacity is reduced due to the parity data blocks.