I have one ST200FM0073 (Seagate SAS SSD, 185 GB, 12GB/s) as cachecade drive. When I use it to cache RAID 5 i get worse results than without using that SSD as the cache.
In other words:
- SSD as independent virtual drive (not CC drive) has performances 1 GB/s read/write. (SSD 12GB/s)
- SSD as CC on RAID 5 reduces speed of raid to 400MB/s (6x 4TB Seagate SAS 6GB/s drives)
- RAID 5 without CC goes to 900 MB/s (6x 4TB Seagate SAS 6GB/s drives)
What is happening here ???
In other words:
- SSD as independent virtual drive (not CC drive) has performances 1 GB/s read/write. (SSD 12GB/s)
- SSD as CC on RAID 5 reduces speed of raid to 400MB/s (6x 4TB Seagate SAS 6GB/s drives)
- RAID 5 without CC goes to 900 MB/s (6x 4TB Seagate SAS 6GB/s drives)
What is happening here ???
Last edited: