Re: hard-disk via virtio-blk under windows (discard_granularity=0)
On Sat, Nov 16, 2024 at 12:57:33AM +0800, d tbsky wrote:
> Based on whether it is taking time in the guest or in the host
you could
> theoretically try setting <driver name='qemu'
discard='ignore'/> but I
> guess that would not help.
no it won't help. I had tried that before. I tried many parameters and
also tried to set the "media type" manually at windows (the function
seems only designed for storage pools, not normal devices).
"discard_granularity=0" is the first parameter which is working. I am
glad that it works. or I can only stay with very old drivers or
replace virtio-blk with virtio-scsi.
Based on your description of the situation, it honestly sounds like
setting discard_granularity=0 is a workaround and what we should
really have is a supported way to control whether the device shows up
as HDD or SSD.
I'm not sure whether this would have to be an option passed to the
QEMU virtio-blk device or some tunable in the driver.
I'd also be surprised if this only affected Windows. Wouldn't Linux
guests likely see a similar change in how the device is presented?
--
Andrea Bolognani / Red Hat / Virtualization