Edge Applications

To meet the performance needs of Edge applications that require sequential operations and multithreaded access for capturing, processing, and storing important data, it's crucial to use storage systems that can deliver exceptional performance.

We have assessed the performance of the Western Digital Ultrastar® DC SN650 drives, protected by Xinnor’s software RAID on a Cheetah RAID Raptor platform, to determine if the combined solution meets these high-performance requirements.

Read the full version of white paper by WD, Cheetah RAID and Xinnor:

White paper (pdf, 1.7 MB)

Challenge

The primary purpose of conducting the assessment was to establish a RAID protection mechanism tailored specifically for Edge applications, with a distinct focus on eliminating the performance limitations often observed in traditional RAID setups. This approach sought to overcome the conventional challenges associated with RAID implementations, paving the way for enhanced reliability and data security without compromising on the demanding performance demands of modern Edge computing scenarios.

Test Setup

Edge Applications - Test Setup

CPU: AMD EPYC 7443P 24-Core Processor; Thread(s) per core: 1; Core(s) per socket: 24.

Motherboard: Supermicro H12SSL-i.

RAM: Micron DIMM DDR4 Synchronous Registered (Buffered) 3200 MHz, 256GiB.

Drives: 12 * Western Digital Ultrastar® DC SN650, 7.68TB.

OS: Oracle Linux 8.4, Kernel: Linux 5.4.17-2102.203.6.el8uek.x86_64.

Server platform: Cheetah RAID Raptor

SSD: 12*Western Digital Ultrastar DC SN650 NVMe™ Enterprise SSDs

RAID Engine: xiRAID 4.0, Level: 5, Stripe: 128K.

Drive Performance

To test the performance of the xiRAID engine, 3 RAID 5 arrays of 4 disks each were created. RAID options were tuned as follows: Scheduling was enabled, merge was disabled by default. Tests were conducted using the FIO utility. Block size was changed to 384K for sequential write tests.

Test results:

Edge Applications - Drive Performance - 1

RAID efficiency is calculated as percentage of the theoretical maximum performance considering the RAID 5 impact:

Edge Applications - Drive Performance - 2

Filesystem Performance: EXT4 vs XFS

Sequential write performance on different file systems was compared using a full-size LUN on RAID. Initially formatted with EXT4, tests were conducted to ensure adequate performance for processing up to four streams of uncompressed 4K video. After preconditioning, RAID was recreated, and the full-size LUN was formatted to XFS for further testing.

Plan of filesystems comparison:

  1. Preconditioning of the drives.
  2. RAID and volume creation.
  3. Testing with frametest.
  4. Long frametest run until the drives are fully written.
  5. Repeating the test with frametest.

Frametest parameters: -w 4k -t 4 -n 9000 (write 4k quality in 4 threads for 9000 frames).

Edge Applications - Filesystem Performance: EXT4 vs XFS

Conclusion

The results of performance tests of the NVMe drives demonstrate performance close to the declared specification. Additionally, the test results of RAID block devices indicate that the performance of the NVMe drives included in the RAID array is nearly equivalent to the combined performance of the individual drives. This highlights the high efficiency of the xiRAID engine. The volume formatted in EXT4 filesystem shows a better sequential write performance even after the drives have been completely written.

Based on these findings, we can conclude that Western Digital Ultrastar® DC SN650 drives protected by Xinnor xiRAID software RAID and operated in Cheetah RAID Raptor platform, deliver sufficient performance to handle up to 4 streams of uncompressed 4k video, meeting the requirements of Edge applications.