>>> On 7/7/2015 at 02:36 PM, in message <559b7366.5030...@kamp.de>, Peter Lieven <p...@kamp.de> wrote: > Am 07.07.2015 um 08:34 schrieb Chun Yan Liu: > > > >>>> On 7/7/2015 at 02:19 PM, in message <559B6F79.237 : 102 : 21807>, Chun > >>>> Yan > Liu > > wrote: > >> > >>>>> On 7/7/2015 at 02:03 PM, in message <559b6bbe.3050...@kamp.de>, Peter > >>>>> Lieven > >> <p...@kamp.de> wrote: > >>> Am 07.07.2015 um 07:59 schrieb Chun Yan Liu: > >>>> > >>>>>>> On 7/7/2015 at 01:50 PM, in message <559b68b2.5060...@kamp.de>, Peter > >>>>>>> Lieven > >>>> <p...@kamp.de> wrote: > >>>>> Am 07.07.2015 um 03:50 schrieb Chun Yan Liu: > >>>>>>>>> On 7/6/2015 at 06:42 PM, in message <559a5b79.4010...@kamp.de>, > >>>>>>>>> Peter Lieven > >>>>>> <p...@kamp.de> wrote: > >>>>>>> Am 06.07.2015 um 11:44 schrieb Chun Yan Liu: > >>>>>>>> While testing with a 1GB VHD file created on win7, found that the > >>>>>>>> VHD file > >>>>>>>> size reported on Windows is different from that is reported by > >>>>>>>> qemu-img > >>>>>>>> info or within a Linux KVM guest. > >>>>>>>> > >>>>>>>> Created a dynamic VHD file on win7, on Windows, it is reported > >>>>>>>> 1024MB > >>>>>>>> (2097152 sectors). But with qemu-img info or within a Linux KVM > >>>>>>>> guest, > >>>>>>>> it is reported 1023MB (2096640 sectors). > >>>>>>>> > >>>>>>>> The values in the footer_buf are as follows: > >>>>>>>> creator_app: "win " > >>>>>>>> cylinders: 0x820 (2080) > >>>>>>>> heads: 0x10 (16) > >>>>>>>> cyl/sec: 0x3f (63) > >>>>>>>> current_size: 0x40000000 (1G) > >>>>>>>> > >>>>>>>> So, if using current_size, it's correct; but using CHS will get a > >>>>>>>> smaller > >>>>>>> size. > >>>>>>>> Should we add a check in this case and use "current_size" instead of > >>>>>>>> CHS? > >>>>>>> > >>>>>>> As far as I remember the issue was and still is that there is no > >>>>>>> official > >>>>>>> spec that says > >>>>>>> use current_size in case A and CHS in case B. > >>>>>> Understand. > >>>>>> > >>>>>>> > >>>>>>> If currrent_size is greater than CHS and Windows would use CHS (we > >>>>>>> don't > >>>>>>> know that) we might run into issues if Qemu uses current_size. In > >>>>>>> this > >>>>>>> cas we would write data beyond the end of the container (from Windows > >>>>>>> perspective). > >>>>>> That's right. The fact is in our testing we found Windows does not use > >>>>>> CHS > >>>>>> but current_size (from testing result), we create and get the VHD > >>>>>> parted on > >>>>>> Windows, then take the VHD file into Linux KVM guest, it fails to show > >>>>> partition > >>>>>> table (since the reported disk size is shrinking, some of the > >>>>>> partitions > >>>>> extend > >>>>>> beyond the end of the disk). > >>>>> > >>>>> Which version of Windows are you referring to? > >>>> Tested with WS2012R2 and Win7. > >>> > >>> Which storage driver? > > And imported to a Win7 guest on KVM as IDE device, it's also reported as > > 1024MB (not CHS value, CHS is 1023MB). > > And what storage driver reports 1023MB under Qemu?
SCSI driver under Linux guest. > > Peter > > > >
