
140 DS8800 Performance Monitoring and Tuning
Figure 4-19 Basic scheme for rank and DA pair association in relation to extent pool planning
This example represents a homogeneously configured DS8700 with four DA pairs and 32
ranks that are all configured to RAID 5 and a DS8800 with four DA pairs and 24 ranks. Based
on the specific DS8000 hardware and rank configuration, the scheme typically becomes more
complex for the number of DA pairs, ranks, different RAID levels, drive classes, spare
distribution, and storage types. The DS8700 with the LFF disk enclosures differs from the
DS8800 with the SFF disk enclosures. Also, be aware of the difference ...