Home > Workload Solutions > Oracle > White Papers > Dell PowerMax 2500 and 8500 Best Practices for Mission Critical Oracle Databases > Number and size of devices
PowerMax uses thin devices exclusively, which means that storage capacity is only consumed when applications write to the devices. This approach allows for capacity savings because storage is only consumed with actual demand.
PowerMax host devices can be sized from a few megabytes to multiple terabytes. Therefore, the user might be tempted to create only a few large host devices. Consider the following for volumes designated for database files:
There is no one size that fits all databases. However, for the size and number of host devices, it is recommended that a small number that offers enough concurrency and adequate building blocks for capacity increments should be used.
Until Oracle release 12.1, ASM disk size was limited to 2 TB. With later releases, ASM allows for larger sizes. Therefore, eight to sixteen data devices and four to eight log devices are often sufficient for high-performance databases of up to 32 TB (16 data devices x 2 TB = 32 TB). For databases larger than 32 TB, more devices might be needed to satisfy the capacity requirements of the database.