Persistent Disk Capacity
Persistent disks bill on the size you provisioned, not the space you filled, and they keep billing while the disk exists — including after the VM attached to it is deleted. Orphaned disks are one of the most common forms of pure waste on a Google Cloud bill.
Billed: Per gibibyte-month PROVISIONED, not used. Rates differ sharply between Standard, Balanced, SSD, and Extreme.
What triggers this charge
- Every provisioned gibibyte, whether the filesystem is 5% or 95% full.
- Disks left behind when an instance is deleted without the "delete boot disk" option.
- Snapshots, which bill separately and accumulate on a schedule nobody reviews.
- Disk type: SSD costs several times Standard for the same capacity.
How to reduce it
Find and delete unattached disks
A disk with no attached instance is doing nothing at all. This is usually the largest single item in the family and the easiest to act on.
Match the disk type to the IO requirement
Balanced PD serves most general-purpose workloads at well under SSD prices. SSD is worth it for databases and little else.
Put a retention policy on snapshots
Snapshot schedules without expiry grow forever. Incremental snapshots are cheap individually and expensive in aggregate.
Rates
Related charges
Now find out how much of this you are actually paying.
Finitizer breaks your Google Cloud bill down to the SKU, shows how each one has moved since last week, and separates rate changes from usage changes — so you know whether to talk to engineering or to procurement.