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8 Dell EMC PowerVault ME4 Series and Microsoft Exchange Server 2016 | 3925-BP-EX
• Disk sparing is performed at the array level. This limits contact and access requirements for servers.
All drives are hot-pluggable and will automatically spare and rebuild in case of replacement or failure.
Spares are shared among disk groups to reduce the number of spares required.
• ME4 Series arrays support SAS, Fibre Channel, and iSCSI in the same platform. Based on
requirements, one or more of these may be used to access the same volumes. This can provide
greater accessibility and performance to any volume than by using local direct attach to a single disk,
and can accelerate backups.
• ME4 Series arrays can host multiple servers on the same array. If choosing to share the drives with
other applications, this can be done quickly and easily.
Exchange Server 2016 supports 100 databases per server with up to 16 copies of each to other Mailbox
servers in a DAG organization. A best practice is to minimize the number of databases to as few as recovery
objectives will allow. As the number of databases increases, so does the I/O required supporting the
additional data streams. This can have a negative impact on the I/O load of a system.
As environments grow larger and larger, it becomes common to run out of drive letters for the volumes. For
the purpose of scalability, it may be suitable to use Windows mount points for database and log volumes.
Table 2 shows a sample disk layout based on best practices using mount points.
Sample disk layout using mount points
Drive
Recommended configuration
Contents
C:
DAS/SAN
Windows, Exchange binaries
D:
DAS (if available)
Pagefile
C:\DB
SAN
Mount points
VMP
C:\DB\Database1
Database 1 and Database 1 logs
VMP
C:\DB\Database2
Database 2 and Database 2 logs
VMP
C:\DB\Database3
Database 3 and Database 3 logs
2.2 Disk groups and pools
The design of the ME4 Series array is based around groups of disks. There are two types of storage available
in the ME4 Series array: virtual and linear storage.
Linear storage maps directly to a single drive or multiple disks, but has less flexibility when it comes to making
changes.
The newer method is virtual storage. Virtual storage starts with disk groups of the chosen RAID type. The
groups of disks are added to a pool, and the volumes are then created from these pools. This allows groups
of disks to change in number and scale larger, providing potential for growth with less effort. Existing groups
and pools can be expanded.
By design, an ME4 Series system in virtual storage mode will have at least one storage pool. In systems with
more than 12 drives, it may have two pools, one for each controller. This is based on how the ME4 Series
array handles volume management. In a two-copy DAG configuration, this can provide I/O isolation if
sufficient drives are available.