Simply using disk arrays won??™t, by itself, give you optimal I/O performance. As discussed
earlier, you also need to logically place the different types of Oracle files
across the available drives, even if the drives are grouped into arrays. As of Oracle
Database 10g, striping considerations are made simpler through Automatic Storage
Management. ASM provides automatic striping and rebalancing of stripe sets. By
default, ASM also provides automated mirroring.
Volume managers
With host-based striping, logical volume-management software runs on the database
server. Examples of this type of software often used under older Oracle database
releases include Hewlett Packard??™s Logical Volume Manager (LVM) and Veritas Software??™s
Volume Manager. The LVM acts as an interface between the operating system
that requests I/O and the underlying physical disks. Volume-management software
groups disks into arrays, which are then seen by the operating system as single
???disks.??? The actual disks are usually individual devices attached to controllers or
disks contained in a prepackaged array containing multiple disks and controllers.
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