Performance benefits
Dell PowerMax storage systems provide a high-performance and low-latency platform for Oracle workloads, both operational (OLTP) and analytics (DSS). Performance benefits include:
- Designed for speed—PowerMax systems include NVMe backend media enclosures, dual-ported NVMe flash drives, and a 100 Gb/s InfiniBand fabric.
- Write-back fast cache—PowerMax systems support high-capacity, DRAM-based cache dedicated to application data. The cache is battery protected and considered persistent. As a result, all application writes are acknowledged to the host when registered in the cache, providing low-write latencies. Reads are cached, based on PowerMax machine learning algorithms.
- Host I/O limits and Service Levels (SL)—The PowerMax Host I/O limits feature restricts the IOPS or bandwidth of specific storage groups (SGs). Similarly, SLs set performance goals on SGs. Some customers prefer to set performance limits for nonproduction systems or due to multitenant design (such as for chargeback or service providers).
- Choice of protocol—PowerMax systems offer various communication protocols between the host and storage, including FC, iSCSI, NVMe/TCP, and 64-bit NAS.
Data reduction
Data reduction features include:
- Thin devices—All PowerMax storage devices are created thin by default, meaning that storage capacity is allocated only when an application writes to the device. This method works well with Oracle ASM or Windows. It can also work with Linux file systems such as NTFS, XFS, and EXT4 since only data written by the host is consumed in the storage. For example, adding storage volumes to ASM disk group only consumes minute actual capacity in these volumes for metadata. Later, when datafiles are created, only their actual capacity is consumed.
- Compression and deduplication—The PowerMax data reduction engine uses both inline storage compression and deduplication. PowerMax compression reduces compressible data. PowerMax deduplication can free up to a 100 percent of the storage capacity created by host-based copies, such as RMAN duplicate creates. For more information about PowerMax data reduction, see PowerMax data reduction and the Dell PowerMax Data Reduction White Paper.
- Online storage reclamation with ASM Filter driver—ASM filter driver (AFD), when used with PowerMax, can provide online storage reclamation. The ASM disk group is configured with AFD labels and set with a thin attribute. The storage capacity of deleted ASM objects (such as datafiles) is reclaimed in PowerMax by using an ASM rebalance. AFD uses write-same SCSI commands to reclaim the PowerMax storage capacity quickly and efficiently so it can be made available to other applications. For more information about ASM and PowerMax data reduction, see ASM and storage reclamation.
Local replication
PowerMax TimeFinder/SnapVX (snapshots) and TimeFinder/Clone (clones) include the following features:
- Consistency—All snapshots are natively storage-consistent (restartable database replicas). Snapshots can become application-consistent (recoverable database replicas) when they are integrated with other software products such as Dell AppSync, allowing database roll-forward recovery. PowerMax clones require the use of the -consistent flag to achieve the same result. Starting with Oracle 12c, Oracle valid backups can be created using storage consistent snapshots and clones, without the use of hot-backup mode.
- Protection—All snapshots are protected. A snapshot can be restored repeatedly (for example, during patch testing until it is successful). Also, a snapshot can be linked to target volumes that are then mounted by another host. Any changes to the target volumes do not affect the original snapshot’s data. While PowerMax clone target volumes can also be restored repeatedly regardless of changes to the source volumes, changes to the clone targets affect future use of the clones.
- Naming—All snapshots are given a user-friendly name when they are created. When the same name is used, a new generation of the snapshot is created for ease of management.
- Automatic expiration—Optionally, snapshots can be given an automatic expiration date and time.
- Security—Snapshots can be made secure, meaning a snapshot cannot be deleted before their expiration date.
- Snapshot options—Snapshots can be taken spontaneously, scheduled by using Unisphere, or automated by using snapshot policies.
For more information about PowerMax snapshots and clones, see Appendix 1. PowerMax replication and the Dell PowerMax 2500 and 8500: TimeFinder SnapVX Snapshots and Clones White Paper.
Remote replication
PowerMax SRDF provides various replication modes and topologies, including synchronous and asynchronous modes, cascaded, Star, and Metro (active/active capabilities that work with Oracle ASM and extended RAC solution). In addition, SRDF is tightly integrated with PowerMax snapshots and clones, providing seamless use of both for solutions such as remote copies and replication of database copies.
For more information about SRDF/Metro, see Appendix 1. PowerMax replication and the Dell PowerMax and VMAX All Flash: SRDF/Metro Overview and Best Practices White Paper.