Disk metrics

The disk can be the first bottleneck for your virtual environments; for this reason, it's very important to understand how much is used and how it is used, both for the capacity (but this could be quite easy) and for the expected performance. Using a simple input/output operations per second (IOPS) approach could work in several cases, but does not appropriately qualify the type of I/O and cannot always help in the storage sizing and design. Storage will be discussed in detail in Chapter 7, Advanced Storage Management.

For the disk, the following table lists some of the common metrics:

Table 3.3: Some of the common metrics for disks