Developers Guide

ASM best practices with SC Series storage
14 Dell EMC SC Series Storage with Oracle ASM | CML1111
If partitioned devices are used, attempting to expand the size of a disk that is not the primary partition requires
advanced knowledge of Linux systems and Oracle backups and should only be done after careful planning
and consideration. This includes making sure a valid backup exists of the entire database.
When not using ASMLib, it might be advantageous to use an entire disk and not a partition to ease the
administration and management of the disk should the disk increase in size. Additional information on resizing
a LUN can be found in the Dell EMC SC Series with Red Hat Enterprise Linux 6x best practices document. If
ASMLib is used, the disk must be partitioned per Oracle requirements. The first partition will be used by
ASMLib to save its metadata, and the remaining portion of the disk will be used by the database.
Dell EMC recommends creating an even number of LUNs per disk group in a dual-controller array since SC
Series storage will automatically balance volumes across both controllers, resulting in I/O activity being more
balanced across controllers.
Having fewer disks per ASM disk group minimizes the administration headaches for DBAs, system
administrators, and storage administrators. However, consider using more than two disk groups if possible.
If necessary, disk groups may contain more than two ASM disks. Multiple disks provides a way to take
advantage of multiple disk queues at the operating-system level and helps if the HBA is not saturated.
If possible, use ASM external redundancy on all ASM disks provisioned from SC Series volumes.