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ME4 Series features
9 Dell EMC PowerVault ME4 Series and VMware vSphere | 3922-BP-VM
operating/redundancy mode is shown as active/active ULP. ULP uses the Asymmetric Logical Unit Access
(ALUA) extensions to negotiate paths with the ALUA-aware operating systems. If the hosts are not ALUA-
aware, all paths are treated as equal even though some paths might have better latency than others.
vSphere ESXi is an ALUA aware operating system, and no additional configuration is required. Each
datastore will have two, four, or eight active paths depending upon controller configuration (SAS, combined
FC/iSCSI controller, or dedicated FC/iSCSI) with half of the paths identified as active optimized and the other
half identified as active non-optimized.
2.4 RAID data protection levels
ME4 Series arrays support RAID data protection levels NRAID, 0, 1, 10, 3, 5, 50, 6 and ADAPT. ADAPT is a
special RAID implementation that offers some unique benefits. It can withstand two drive failures with very
fast rebuilds. Spare capacity is distributed across all drives instead of dedicated spare drives. ADAPT disk
groups can have up to 128 drives and allow mixing different drive sizes. Data is stored across all disks evenly.
The storage system automatically rebalances the data when new drives are added or when the distribution of
data has become imbalanced.
It is recommended to choose the right RAID level that best suits the type of workloads in the environment.
Review the information in ME4 Series Administrator's Guide on Dell.com/support which details the benefits of
each RAID level, the minimum and maximum disks requirements, and the recommendation of RAID levels for
popular workloads.