Understanding persistent disks and local SSDs

Standard HDD persistent disks are efficient and economical for handling sequential read/write operations, but are not optimized to handle high rates of random input/output operations per second (IOPS).

If your applications require high rates of random IOPS, use SSD persistent disks. Persistent disks can be attached to multiple instances in read-only mode for data sharing.

One might get confused between Persistent Disks and Cloud Storage Buckets (which we will explore later in this book) since both are cloud storage technologies accessible via a network. But it is important to remember that persistent disks are created for Compute Engine instances via Compute Engine APIs and are accessed via gsutil command line tool not gcloud. Further differences can be noticed in the following table: