Database Reference
In-Depth Information
Table 6.18
IOPS per TB Based on Example 30% Read 5,000 IOPS and 2.5TB Capacity
Note
There are many new storage platforms that include only flash as part of
their architecture, meaning the entire array may become your primary tier.
Some of these platforms claim to offer economics similar to spinning disks,
by using advanced compression and data de-duplication techniques. These
platforms are normally aimed at the highest performance workloads, such
as critical SQL databases. These types of storage platforms are
unsurprisingly known as “All Flash Arrays,” and come from the likes of
EMC, NetApp, HP, PureStorage, Violin Memory, and others.
At this point, you might consider doubling the size of each EFD to 800GB. This would
halve the number of disks required to meet the capacity requirements. Assuming that
each individual 800GB EFD has the same IOPS performance as the 400GB versions,
you could achieve a better balance of performance and capacity. The larger EFDs
would have half the IOPS per TB—in this case, to around 2,000. Five EFDs would be
required to reach the required capacity. This would mean 3.2TB of usable capacity is
deployed. The achievable IOPS from the deployed usable capacity would drop to
6,400. This is still a more performance than required. Also, although we are only using
5 × 800GB EFDs instead of 8 × 400GB EFDs, because they are double the capacity,
they are also likely to be double or more the cost.
An EFD might be marketed at 400GB or 800GB in size, but to protect against wear of
the NAND flash cells, the disk will usually have more physical capacity. This is to
provide more endurance and a longer service life. This may vary between different
vendors and individual SSDs, and we recommend you check with your storage vendor.
Tip