Diagnosis and Performance Monitoring - Deploying and Managing a Cloud Infrastructure - page 146

Object R/W Requirement Disk R/W capability Disks needed

A 100 reads 48 reads 2.02

B 100 writes 32 writes 3.04

C 100 writes 32 writes 3.04

8.1 (9)

In our example tabulation, we need 8.1 disks to be able to support 100 transactions per
second, but since we cannot come up with 1/10 of a disk, it's better to round up than down
because it is the safer alternative in terms of performance. So we now have a clear under-
standing of our hardware requirement.
If you already have a system in place and it is not performing as expected, follow these
steps to determine if the system is configured with enough hardware resources first before
moving on to the next tuning methods.

Business Application for Disk Tuning

Disk tuning is important for one simple reason: the disk is the slowest part of the computer
system. So in a lot of scenarios, the disk is the bottleneck, which means almost all I/O opera-
tions are bottlenecks. This is more strongly felt in systems that manage and manipulate a lot
of data, like the ones being used by stock-trading organizations, for example. In the rapidly
changing and volatile world of trading, the environment can change in an instant, which
means new data keeps flooding in every minute. And for the system to analyze such large
data sets, they would have to be quickly written into disk so that they can be processed and
analyzed. This constant reading and writing will add latency to analysis programs, which
may negatively affect the ability to arrive at timely decisions because the system is taking a
long time to process analysis reports.

Performance Management and Monitoring Tools

It is important to note that storage is not the only thing that matters in a cloud system.
Although it has a major influence on usage percentages, we still need to manage and monitor
all aspects of the cloud system. Most major cloud computing system vendors offer manage-
ment tools. But there are a lot of third-party management software programs that integrate
with cloud platforms from most vendors.