Re: [Qemu-devel] QCOW image corruption under QEMU 0.9.0

[J M Cerqueira Esteves]

J M Cerqueira Esteves wrote:
> Curiously this damaged image file has 4543348736 bytes.
> I wonder if there some new bug triggered by the image file size,
> for some size around 4500000000 bytes...

I have a copy of the disk image file as it was just before starting the
qemu run which damaged it, and now I noticed that, during that qemu run,
the image file size did not change: 4543348736 bytes.

However, comparing both images with  cmp -l  shows extensive changes.
Just an example, from the first bytes (byte number, original value,
corrupted value):

         1 121   0
         2 106   0
         3 111   0
         4 373   0
         8   2   0
        24  14   0
        28   5   0
        39  50   0
        47  20   0
        52   1   0
        55  20   0
        60   2   0
      1881   0 200
      1887   0  40
      1889   0 200
      1895   0 100
      9049 200   0
      9054   1   0
      9055 220   0
      9057 200   0
      9061  60   0
      9062 115   0
      9063 100   0
... many more zeroed out...
     49487 220   0
     49569 200   0
     49573 325   0
     49574 357   0
     49575 300   0
     49665   0 147
     49666   0 145
     49667   0  55
     49668   0  62
     49669   0  56
     49670   0  66
     49671   0  56
     49672   0  61
     49673   0  70
     49674   0  55
     49675   0  63
     49676   0  55
     49677   0 153
 ... many more un-zeroed ...
     49853   0  40
     49854   0 151
     49855   0 163
     49856   0  40
     49857 200 141
     49858   0 166
     49859   0 141
     49860   0 151
     49861  46 154
     49862 174 141
     49863 140 142
     49864   0 154
     49865   0 145
 ... many more un-zeroed ...
     49983   0 142
     49984   0 157
     49985 200 157
     49986   0 164
     49987   0  40
     49988   0 171
     49989  15 157
     49990 354 165
     49991 200 162
     49992   0  40
     49993 200 155
     49994   0 141
     49995   0 143
     49996   0 150
     49997  16 151
     49998   1 156
     49999 260 145
     50000   0  56
     50001   0  12
     50002   0  12
    ...

Best regards
                                                     J Esteves