Performance benefits
PowerMax systems provide a high-performance and low-latency platform for SQL Server workloads, both operational (OLTP) and analytics (DSS). Performance benefits include:
- Designed for speed—The PowerMax storage system includes NVMe backend media enclosures, dual-ported NVMe flash drives, and a 100Gb/s InfiniBand fabric.
- Write-back fast cache—The PowerMax storage system supports high-capacity DRAM-based cache dedicated to application data. The DRAM-based cache is battery protected and considered persistent. As a result, all application writes are acknowledged to the host when they are registered in the cache, providing low-write latencies. Reads are cached, based on PowerMax machine learning algorithms.
- Microsoft ODX—The Offload Data Transfer (ODX) feature of Windows Server and Hyper-V is a Microsoft technology that allows offloading data copy operations, which are normally performed by host reads and writes, to be performed internally by the storage system. PowerMax systems support ODX offload copy operations and provide best copy efficiency when NTFS is formatted with a 128 KB allocation unit.
- Host I/O limits and Service Levels (SL)—Some customers prefer to set performance limits for nonproduction systems or due to multitenant design (for example, for chargeback or for service providers). The PowerMax Host I/O limits feature caps the IOPS or bandwidth of specific storage groups (SGs). Similarly, SLs set performance goals on SGs.
- 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, which means that storage capacity is allocated only when the application writes to them. This method works well with Windows and Linux file systems such as NTFS, XFS, and EXT4 because file system creation does not write more than the necessary metadata.
- 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.
For more information about PowerMax data reduction, see the Dell PowerMax Data Reduction white paper.
Local replication
PowerMax TimeFinder/SnapVX (snapshots) and TimeFinder/Clone (clones) include the following features:
- Consistency—All snapshots are natively “storage-consistent” (restartable database replicas). Integrated with other software products such as Dell AppSync, the snapshots can become “application-consistent” (recoverable database replicas), allowing database roll-forward recovery. PowerMax clones require the use of the -consistent flag to achieve the same result. With the SQL Server 2022 Transact-SQL snapshot backup feature, SQL Server backups can be created directly (without a third-party application) using storage consistent snapshots and clones.
- 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 get 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 on which they terminate.
- Security—Optionally, snapshots can be made secure. Secure snapshots cannot be deleted before their expiration date.
- Snapshot options—Snapshots can be taken at any time spontaneously, can be scheduled by using Unisphere, or can be automated by using snapshot policies.
For more information about PowerMax snapshots and clones, see the Dell PowerMax 2500 and 8500: TimeFinder SnapVX Snapshots and Clones white paper.
Remote replication
PowerMax SRDF provides various replication modes and topologies, which include synchronous and asynchronous modes, cascaded, Star, and Metro (active/active capabilities that work well with Windows Cluster technology). In addition, SRDF is tightly integrated with PowerMax snapshots and clones, providing a seamless use of both for solutions such as remote copies, replications of database copies, and more,
For more information about SRDF/Metro, see the Dell PowerMax and VMAX All Flash: SRDF/Metro Overview and Best Practices white paper.