Home > Storage > Unity XT > Virtualization, Cloud & Applications > Dell Unity XT: Oracle Database Best Practices > Storage pools
In general, it is recommended to use fewer storage pools within Dell Unity systems. Fewer storage pools reduce complexity and increases flexibility. Dell Technologies recommends using a single virtual disk pool for hosting volumes for Oracle databases. A single virtual pool provides better performance by leveraging the aggregate I/O bandwidth of all disks to service I/O requests from Oracle databases. A single drive pool is easier to manage, allowing an administrator to easily adapt the storage system to satisfy ever-changing workloads that are common in Oracle databases environments. Before creating multiple storage pools to separate workloads, understand the various Dell Unity features that are available for managing and throttling specific workloads.
By default, the Dell Unity system chooses RAID 5 as the protection level when creating a storage pool which contradicts traditional guidance advocating RAID 1/0 for database workloads. However, this traditional guidance assumes the storage system contains spinning disks and does not consider SSDs or flash-optimized storage such as Dell Unity systems. Testing Dell Unity All-Flash systems in most RAID 5 and RAID 1/0 configurations has shown negligible performance gains unless the workload is extremely write-intensive for an extended period. Usually, the small performance gain of RAID 1/0 is not worth the reduced capacity and therefore it is recommended to use the default configuration of RAID 5. For heavy write workloads where maximum write performance is required, RAID 1/0 can be used.
The I/O requirements need to be clearly defined to size storage correctly. The RAID type chosen will be determined by comparing availability and performance requirements. The small footprint and high IO density will typically allow a smaller drive size, reducing drive rebuild times, which means RAID 5 would be preferred over RAID 6 usually.