The following are some best practices when running Oracle RAC on ASM with PowerFlex and Oracle Linux KVM.
- If possible, use different ASM disk groups for each database function. The groups should use external redundancy. This provides for greater flexibility.
- DATA for data
- REDO for redo logs
- FRA for archive logs
- CONFIG for voting disk
- Use multiple storage domains for each ASM disk group with a single, shared virtual disk in each that consumes the space. This makes it easier to increase or decrease ASM disk groups and provide more concurrency.
- On each VM, the shareable disks must be owned by oracle with a permission mode of 0660.
- Members of an ASM disk group should be of similar capacity. If devices are initially sized large, each capacity increment to the ASM disk group will need to be as large.
- Oracle ASM best practice is to add multiple devices together to increase the ASM disk group capacity rather than adding one device at a time. This method spreads ASM extents during rebalance to avoid hot spots. Use a device size that allows for ASM capacity increments, in which multiple devices are added to the ASM disk group together. Each device should have the same size as its original device.