Basic (conservative) configuration of the day jobs’ high performance tightly coupled storage system, no SSDs (apart from the OS drives). RAID6 LUNs, no RAID0’s. This is spinning rust folks. Nothing but spinning rust. In a realistic configuration.
And no, we haven’t yet begun to tune this.
Streaming writes, 1 thread per LUN:
Run status group 0 (all jobs): WRITE: io=1279.5GB, aggrb=5944.6MB/s, minb=5944.6MB/s, maxb=5944.6MB/s, mint=220405msec, maxt=220405msec
5.9 GB/s sustained writes for this case. Writing 1.3 TB of data. In 220s. In a single 4U rack space. 160TB of usable space (out of 240TB in the unit). Lots of hot spares (so it detracts from the overall performance).
Streaming reads, 1 thread per LUN:
Run status group 0 (all jobs): READ: io=1279.5GB, aggrb=5979.3MB/s, minb=5979.3MB/s, maxb=5979.3MB/s, mint=219116msec, maxt=219116msec
This is a respectable 5.9 GB/s sustained reads.
I should also point out that we are using effectively 40 data drives for this (60 drives – (2x hot spare + 2x parity drives/LUN) * 5 LUNs = 40 effective data drives). Call it 6GB/s for 40 drives, and we are averaging about 150MB/s per drive. Which is within a small delta of the overall per unit bandwidth of the drives … very nearly 160 MB/s for these. Call it about 94% bandwidth efficiency per drive.