RAID Controllers and Storage Arrays

The DataCore Server's Boot Disk

Configure the DataCore Server’s own Boot Disk for redundancy. It is recommended to use RAID 1, as this is usually simpler (less complex to configure and has less overhead than RAID 5). It is not recommended to use the same Storage Array controller for the Boot Disk and Pool Disks.

Disks Used for DataCore Disk Pools

RAID and Storage Array controllers used to manage physical disks in Disk Pools need to be able to handle I/O from multiple Hosts connected to the DataCore Server; so, for high performance/low latency hardware, use independent buses or backplanes designed for ‘heavy’ workloads (‘workstation’ hardware is not usually designed for such workloads).

A low-end RAID controller will deliver low-end performance. An integrated (onboard) RAID controller that is often supplied with the DataCore Server may only be sufficient to handle just the I/O expected for the boot drive. Controllers that have their dedicated CPU and cache can manage much higher I/O workloads and many more physical disks. Consult with your storage vendor about the appropriate controller to meet your expected demands.

Intel’s VROC technology (Virtual RAID on CPU) has been tested and qualified as an appropriate high-performance solution for NVMe RAID architectures and can be used with SANsymphony’s storage pools. Availability depends on support from the chosen server vendor, supported NVMe devices, and processor requirements for VROC.

If both 'fast' and 'slow' disk types share the same disk controller in the storage array (e.g., an SSD sharing the same disk controller as a SAS RAID5 set), then the slower disks on that controller can hold up I/O to the faster disks. DataCore’s recommendation is to have a separate disk controller for each differential disk speed type. If there is no choice but to mix different disk speed types on the same disk controller - for example mixing SSD with SAS - then in this example, make sure the SAS disk has 'no RAID' (or RAID0) configured and use SANsymphony's Disk Pool mirroring feature as this should be faster than hardware RAID mirroring.

Also see:

Storage Hardware Guideline for use with DataCore Servers

Mirroring Pool Disks

The DataCore and Host Servers - Qualified Hardware

Known Issues - Third-Party Hardware and Software

A Summary of Recommendations for RAID Controllers and Storage Arrays

RAID Controllers and Storage Arrays

  • Use high-performance/low-latency hardware with independent buses or backplanes designed for ‘heavy’ workloads (‘workstation’ hardware is not usually designed for such workloads).
  • Avoid using ‘onboard’ disk controllers for anything other than the DataCore Servers’ Boot Disks.
  • Intel VROC is qualified for SANsymphony storage pools.
  • Configure the DataCore Server’s Boot Disk for RAID1.
  • Use a separate controller for physical disks used in either Disk Pools or for the Replication buffer.
  • If mixing fast and slow disks on the same controller, then use Disk Pool mirroring instead of hardware RAID on the slower disks.