If it helps, here's the details of the hardware config.
The controller is
AVAGO MegaRAID SAS 9361-4i,
the SSDs are
INTEL SSDSC2KG960G8 (configured as a raid1).
Current scheduler used is deadline.
Currently XFS is mounted without nobarriers, but I'm going to set that when there's high load next time to see how it affects throughput.
Properties of the array
VD6 Properties :
==============
Strip Size = 256 KB
Number of Blocks = 1874329600
VD has Emulated PD = Yes
Span Depth = 1
Number of Drives Per Span = 2
Write Cache(initial setting) = WriteBack
Disk Cache Policy = Disk's Default
Encryption = None
Data Protection = Disabled
Active Operations = None
Exposed to OS = Yes
Creation Date = 28-10-2020
Creation Time = 05:17:16 PM
Emulation type = default
Cachebypass size = Cachebypass-64k
Cachebypass Mode = Cachebypass Intelligent
Is LD Ready for OS Requests = Yes
SCSI NAA Id = 600605b00af03650272c641ca30c3196
Best, Alex