On Sat, Nov 25, 2023 at 05:38:28PM +0000, Michael Kelley wrote: > Hyper-V guests and the Azure cloud have a particular interest here > because Hyper-V guests uses SCSI as the standard interface to virtual > disks. Azure cloud disks can be throttled to a limited number of IOPS, > so the number of in-flights I/Os can be relatively high, and > merging can be beneficial to staying within the throttle > limits. Of the flip side, this problem hasn't generated complaints > over the last 18 months that I'm aware of, though that may be more > because commercial distros haven't been running 5.16 or later kernels > until relatively recently.
I think the more important thing is that if you care about reducing the number of I/Os you probably should use an I/O scheduler. Reducing the number of I/Os without an I/O scheduler isn't (and I'll argue shouldn't) be a concern for the non I/O scheduler.
