RAID50 slow write speed

Question

Initial Configuration:

RAID:

Used Operation System: Windows Server 2016

Result:

CrystalDiskMark Metrics:

Read [MB/s]: 221.5 Write [MB/s]: 38.30

Ubuntu Live CD Metrics:

Read [MB/s]: 270.1 Write [MB/s]: 49.5

Question:

What can I attempt to increase Write Speed?

Should I reconfigure RAID50 settings, or configure different type of RAID?

Is this a new array? What OS? One solution would be to not use "hardware" RAID... (which has other benefits too) — Attie
– Attie, Commented Dec 19, 2018 at 15:53
"Write Through" vs "Write Back" caching will likely affect this significantly, though make sure you have NV cache (or backup power) if you use Write Back. — Attie
– Attie, Commented Dec 19, 2018 at 15:55
So... 6 disks = 2 spans of 3 disks each? Try deleting and recreating the RAID. Use a live CD to test the I/O. You could always try a different RAID type to test. Doing three mirror sets and then I/O test against each might indicate if a drive is the culprit. You could also look to the RAID controller. Make sure you're on the most updated firmware for it from the vendor. — thepip3r
– thepip3r, Commented Dec 19, 2018 at 15:55
Thanks for response. I've updated my question to clarify your notes — AlGiorgio
– AlGiorgio, Commented Dec 19, 2018 at 16:06
Write Back will give you a higher write speed... until your cache fills up... but before enabling it you must make sure that you have NVRAM or suitable backup power (e.g: battery / super cap). — Attie
– Attie, Commented Dec 19, 2018 at 16:16

AlGiorgio · Accepted Answer · 2018-12-19 17:54:50Z

0

Changing Default Write policy to 'WRITE ALWAYS BACK' has aligned rate of speed:

Read [MB/s]: 222.6

Write [MB/s]: 208.8

So it's a good practice to consider this option for write intensive tasks.

answered Dec 19, 2018 at 17:54

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