- Are durable network storage devices that you can provision to host your virtual machine instances.
- Data on each persistent disk is distributed across several physical disks and is designed for high durability. It stores data redundantly to ensure data integrity.
- Persistent disks are resizable to accommodate larger storage requirements.
- It can be attached to virtual machines running on Compute Engine (GCE) or Google Kubernetes Engine (GKE).
- You cannot attach a persistent disk to an instance on another project.
- Your storage is independent of your virtual machine instances so you can detach or move your PDs to keep your data even after you delete your instances.
- You can only change the size of a Persistent Disk incrementally.
Zonal and Regional Persistent Disks
You can configure your PD to be zonal or regional.
- Zonal Disks
- Are relatively faster than Regional disks and are found in a zone.
- Regional Disks
- Provides replication of data between two zones in the same region.
- Is designed for building robust and highly available systems on Compute Engine.
Persistent Disk Types
- Standard (pd-standard)
- Backed by standard hard disk drives (HDD).
- Efficient and economical for handing sequential read/write operations but they aren’t optimized to handle high rates of random input/output per second (IOPS).
- Balanced and SSD Disks
- Backed by solid state drives (SSD)
- SSD persistent disks are designed for single-digit millisecond latencies
- Data on persistent disks are automatically encrypted at rest and in transit by system defined encryption keys or with customer-supplied keys.
- To control your data encryption, you can create PDs with your own encryption keys.
- Persistent disk snapshots can be created to protect against data loss.
- Snapshots are incremental and take only minutes to create even if you snapshot disks that are attached to running instances.
- You can set up a snapshot schedule to back up your data on a regular basis.
- Provisioning persistent disks incurs cost based on the following factors:
- Amount and location of provisioned space per disk
- Snapshot Storage
- Network charges for snapshot creation