gce/BP_EXT/2024_002
Product: Compute Engine
Rule class: BP_EXT - (Extended) Best practice, opinionated recommendation
Description
This lint rules provide a easy method to calculate the Instance’s disk IOPS and Throughput applicable limits and current usage.
Remediation
To understand a VM’s storage performance, view performance metrics for Throughput, Operations (IOPS), I/O Size, I/O Latency, and Queue Length.
Disk throughput and IOPS indicate whether the VM workload is operating as expected. If throughput or IOPS is lower than the expected maximum listed in the disk type chart, then I/O size, queue length, or I/O latency performance issues might be present.
You can expect I/O size to be between 4-16 KiB for workloads that require high IOPS and low latency, and 256 KiB-1 MiB for workloads that involve sequential or large write sizes. I/O size outside of these ranges indicate disk performance issues.
Queue length, also known as queue depth, is a factor of throughput and IOPS. When a disk performs well, its queue length should be about the same as the queue length recommended to achieve a particular throughput or IOPS level, listed in the Recommended I/O queue depth chart.
I/O latency is dependent on queue length and I/O size. If the queue length or I/O size for a disk is high, the latency will also be high.
If any storage performance metrics indicate disk performance issues, do one or more of the following:
- Review Optimizing Persistent Disk performance or Optimize Hyperdisk performance and implement the best practices suggested to improve performance.
- Attach a new persistent disk to the VM or Add Hyperdisk storage to a VM to increase the disk performance limits. Disk performance is based on the total amount of storage attached to an instance. This option is the least disruptive as it does not require a you to unmount the file system, restart, or shutdown the instance.
- Modify the Hyperdisk to increase the per-disk IOPS and throughput limits. For Persistent Disk, you must increase the size of the disk to increase the per-disk IOPS and throughput limits. Disks don’t have any reserved, unusable capacity, so you can use the full disk without performance degradation.
- Change the disk type to a disk type that offers higher performance.