| Message ID | 1435713640-12362-11-git-send-email-jsnow@redhat.com |
|---|---|
| State | New |
| Headers | show |
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
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.
diff --git a/hw/block/fdc.c b/hw/block/fdc.c index 7d4206d..b176aab 100644 --- a/hw/block/fdc.c +++ b/hw/block/fdc.c @@ -72,7 +72,7 @@ typedef struct FDFormat { FDriveRate rate; } FDFormat; -#define FDRIVE_DEFAULT FDRIVE_DRV_144 +#define FDRIVE_DEFAULT FDRIVE_DRV_288 static const FDFormat fd_formats[] = { /* First entry is default format */
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. Signed-off-by: John Snow <jsnow@redhat.com> --- hw/block/fdc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)