Incremental cloud snapshots in ROSA
Summary and Key concepts
Summary:
This article explains how to manage the frequency of full backups in Portworx's CloudSnaps (cloud snapshots). When Portworx uploads backups to the cloud, it starts with a full backup and then follows up with a series of incremental backups. By default, Portworx performs a full backup after every 7 incremental backups. Users can view and change the frequency of full backups using the pxctl command. The article warns that setting a high frequency for full backups can slow down restores, while setting a low frequency will result in more frequent full backups.
Kubernetes Concepts:
- PersistentVolumeClaim (PVC): CloudSnaps are typically used to back up PVC data to the cloud.
- Cluster-wide Configuration: Changes to the CloudSnap full backup frequency apply across the entire Kubernetes cluster managed by Portworx.
Portworx Concepts:
- pxctl Command: A CLI tool for managing Portworx cluster settings, including configuring cloud backup frequencies.
When Portworx takes and uploads backups for cloud snapshots (cloudsnaps), it first takes and uploads a full backup to your cloud provider. After the initial upload, Portworx uploads a series of incremental backups punctuated by an occasional full backup. By default, Portworx uploads a full backup every 7th cloud backup it performs. You can control the frequency with which Portworx uploads a full backup by configuring cluster options.
This is a cluster-wide setting.
View full backup frequency
You can view the currently set frequency by searching for it in the pxctl cluster options list output:
pxctl cluster options list | grep frequency
Cloudsnap full backup frequency : 7
Change full backup frequency
To modify the frequency with which Portworx uploads full backups for cloudsnaps, enter the following pxctl cluster options update command with the --cloudsnap-full-backup-frequency flag and a valid frequency range. The following example updates the frequency to every 4 cloudsnaps:
pxctl cluster options update --cloudsnap-full-backup-frequency 4
If you set the --cloudsnap-full-backup-frequency to a very high value, Portworx may take longer to restore your cloudsnaps, since there's a large number of incremental snapshot data to piece together before reaching a full backup. Additionally, these cloudsnaps may be larger, as they hold more incremental snapshots.
If you set the frequency to a very low value, Portworx will send full backups more often.