484 DS8800 Performance Monitoring and Tuning
We typically cannot predict when the peaks in each LPAR happen, so we cannot predict how
the performance in the other LPARs is influenced.
Many IBM i data centers successfully share the ranks with little unpredictable performance,
because the disk arms and cache in the DS8000 are used more efficiently this way.
Other IBM i data centers prefer the stable and predictable performance of each system even
at the cost of more DS8000 resources. These data centers dedicate extent pools to each of
the IBM i LPARs.
Many BM i installations have one or two LPARs with important workloads and several smaller,
less important LPARs. These data centers dedicate ranks to the large systems and share the
ranks among ...