Release Notes

Optimize an SC Series array for an Oracle data warehouse
12 Optimizing Dell EMC SC Series Storage for Oracle OLAP Processing | 2009-M-BP-O
3.3.2 Linux LVM
Linux Logical Volume Manager (LVM) is a common general-purpose storage manager included in all popular
Linux distributions. Since Oracle software is excluded from ASM, LVM can be used to store the software on a
local Linux file system. Similar to ASM, it is not necessary to mirror logical volumes in LVM. LVM allows
striping data files across multiple volumes in a volume group. Unlike ASM, the striping needs to be configured
by administrators explicitly, and automatic restriping is not available when extending a volume group in LVM.
LVM guidelines:
• Create a dedicated LVM volume group for storing the Oracle software.
• Use two or more volumes (LUNs) in a volume group to increase performance.
• Make sure all volumes in the same volume group have the same volume attributes (such as data
reduction, volume cache, and storage profile on the SC Series array)
• When multiple copies of Oracle software are installed on the server, create one volume group for
each copy of Oracle software. This allows array-based snapshots on individual Oracle software copy.
• Set up a snapshot consistency profile for each multi-LUN volume group. Assign all volumes in the
same volume group to the same snapshot consistency profile.
• In an Oracle RAC configuration, use a dedicated local LVM volume group for each cluster node.
• Enable the discard filesystem option in /etc/fstab, or include -o discard to the mount command.
Certain filesystem types, such as ext4, supports the online TRIM command. This is useful for thin-
provisioned volumes because when deleting files in the filesystem, the associated blocks are also
deleted or released in the SC Series array.
Note: If an SC Series volume is a preallocated volume, to keep the preallocated space, do not enable the
discard filesystem option or run the TRIM command against the file system. Otherwise the space will be
deallocated.
3.4 Achieve greater storage efficiency and performance
A typical data warehouse consumes large amount of storage space to store many years of historical data.
While flash drives offer a significant performance improvement and the cost has come down rapidly in recent
years, they can be more expensive than HDDs, which can also offer a larger capacity per drive. One solution
is to combine both flash drives and HDDs to address the need of a data warehouse in an economical and
efficient way.
3.4.1 Storage tiers and tier redundancy
SC Series arrays support up to three storage tiers. With the advent of flash drives, it is common to have a
two-tier system that consists of SSD drives in tier 1 and HDDs in tier 3. Further optimization and protection
are done within each tier with different RAID levels.
The storage tiers and tier redundancy are automatically configured by SCOS based on the drive types and
sizes. Adjustment to the storage tiers and tier redundancy can be done in DSM at any time. However, it is
recommended to make the adjustment only after careful review and evaluation.