Re: [Qemu-block] [Qemu-devel] [RFC 10/10] fdc: change default drive to 288

[John Snow]

On 07/05/2015 10:53 AM, Kevin O'Connor wrote:
> On Tue, Jun 30, 2015 at 09:20:40PM -0400, John Snow wrote:
>> The 2.88 drive is more suitable as a default because
>> it can still read 1.44 images correctly, but the reverse
>> is not true.
>>
>> Since there exist virtio-win drivers that are shipped on
>> 2.88 floppy images, this patch will allow VMs booted without
>> a floppy disk inserted to later insert a 2.88MB floppy and
>> have that work.
> 
> On real machines, 1.44MB floppy drives were very common.  It was
> exceptionally rare to see 2.88MB floppy drives though.  There is a
> risk that changing the default to an exotic piece of hardware will
> expose quirks in guest Operating Systems.
> 
> -Kevin
> 

Definitely.

Which is why I do want to add some properties to allow users to help
guide the type of floppy drive they get. 2.88MB might well be a saner
default for when no diskette is inserted (It allows for, I believe, the
widest choice of likely types to be inserted later.)

Windows (MSDOS through Windows8) and Linux both seem completely fine,
which I think represents the lion's share of likely guests.

For other guests, you can always tweak the CLI to provide a drive type
the guest can use.