IO profiles


You can optimize the performance of your Portworx volumes by matching the type of workload you’re running with a suitable IO profile. IO profiles change the how a Portworx volume interacts with the underlying storage disks to improve traffic for different workloads.

Understand the different IO profiles

Portworx currently features the following IO profiles:

  • auto
  • db
  • db_remote
  • sequential

The auto profile

If you don’t provide an IO profile, Portworx will default to auto. This profile automatically applies an IO profile that based on congifuration details it sees, and switches between none and db_remote. Portworx chooses db_remote when a volume’s replication factor is greater than or equal to 2, otherwise it defaults to none.

The db profile

Databases typically result in a large number of flush operations on the disk. Because a flush forces Portworx to wait until the data is synched on the disk, it can slow down traffic. When the db profile is active, Portworx batches flush operations for a quicker write response time.

NOTE:

  • If there are not enough nodes online, Portworx will automatically disable this algorithm.
  • The db profile only applies if you have a repl count of 2 or more.

The db_remote profile

This implements a write-back flush coalescing algorithm. This algorithm attempts to coalesce multiple syncs that occur within a 50ms window into a single sync. Coalesced syncs are acknowledged only after copying to all replicas. In order to do this, the algorithm requires a minimum replication (HA factor) of 2. This mode assumes all replicas do not fail (kernel panic or power loss) simultaneously in a 50 ms window.

NOTE:

  • If there are not enough nodes online, Portworx will automatically disable this algorithm.
  • The db_remote profile only applies if you have a repl count of 2 or more.

The sequential profile

This profile optimizes the read-ahead algorithm for sequential workloads, such as backup operations.

Configure profiles

You can configure IO profiles through Kubernetes specs or at the Portworx level, depending on your needs and what operator you’re running with.

For information about how to configure IO profiles for volumes on Kubernetes clusters, follow this link:

For information about how to configure IO profiles from volumes using pxctl, follow this link:



Last edited: Thursday, Aug 11, 2022