Hi,
When SSD storage is present in a Storwize array it can be used in two ways:
- As a dedicated storage tier where you are able to use the SSD capacity to provision volumes to your host systems. In a system with SSD and traditional disk, you will end up with two storage pools, one for each tier.
- To create an EasyTier configuration. This is when you have a storage pool made up of traditional disks but then add some of your SSD capacity to the pool. Storwize will then migrate hot blocks of data to the SSD storage to improve the performance of the whole storage pool. With this option you do not specify which tier within the pool to create the volume on, you just create the volume in the pool and some SSD storage will be used based on the performance characteristics of data blocks.
Hope this makes sense
Darren Sanders
Principal Consultant
Celerity Ltd
http://www.celerity-uk.com