E10-001 · Question #22
E10-001 Question #22: Real Exam Question with Answer & Explanation
The correct answer is A. Write-through cache. Write Operation with Cache Write operations with cache provide performance advantages over writing directly to disks. When an I/O is written to cache and acknowledged, it is completed in far less time (from the host's perspective) than it would take to write directly to disk. Seq
Question
Exhibit
Options
- AWrite-through cache
- BWrite-back cache
- CWrite aside cache
- DWrite cache vaulting
Explanation
Write Operation with Cache Write operations with cache provide performance advantages over writing directly to disks. When an I/O is written to cache and acknowledged, it is completed in far less time (from the host's perspective) than it would take to write directly to disk. Sequential writes also offer opportunities for optimization because many smaller writes can be coalesced for larger transfers to disk drives with the use of cache. A write operation with cache is implemented in the following ways: - Write-back cache: Data is placed in cache and an acknowledgment is sent to the host immediately. Later, data from several writes are committed (de-staged) to the disk. Write response times are much faster because the write operations are isolated from the mechanical delays of the disk. However, uncommitted data is at risk of loss if cache failures occur. - Write-through cache: Data is placed in the cache and immediately written to the disk, and an acknowledgment is sent to the host. Because data is committed to disk as it arrives, the risks of data loss are low, but the write-response time is longer because of the disk operations.
Community Discussion
No community discussion yet for this question.