Google Cloud Persistent Disk Description
Block storage that is reliable and high-performance for virtual machine instances. HDD is a low-cost storage option when bulk throughput is important. SSD provides consistent high performance for random-access workloads as well as bulk throughput. Both can be sized up 64 TB. Multi-reader mounting allows multiple virtual machines to read data from one Persistent Disk. The aggregate performance and cost of attaching a disk to multiple virtual machines is not affected. You no longer need to worry about undersizing block devices. Persistent disk gives you unlimited flexibility. It allows you to resize storage while it is being used by one or more virtual machine without any downtime. Snapshots can be geo-replicated, which means they are available for restoration in all regions. This allows you maximum flexibility and minimal effort. Snapshots of a block devices can be taken in minutes, rather than hours. Persistent disks are automatically encrypted to ensure your data is protected in transit and at rest.