| 2009-04-07 06:16:41 |
Porcelain Mouse |
description |
Binary package hint: kvm
KVM Version: 1:72+dfsg-1ubuntu6
QEMU Version: 0.9.1-5ubuntu3
Description: Ubuntu 8.10
Release: 8.10
File Data and Filename corruption occurs when coping large files to a Virtual FAT (VFAT) drive. I noticed this when copying ISO images between 150MB and 200MB from WindowsXP guest to the Linux host. These ISO images would not boot. Suspecting corruption, I confirmed MD5 hash values of guest and host copies of these ISO images were different. (In fact, the guest OS calculated the correct hashes of the files on the VFAT drive after copying.)
Also, filename corruption also occurred. For example, the VFAT directory on the host contained the file "pebuilder3110a.zip". After "exporting" files named "pebuilder.iso", "pebuilder.log", and "pebuilder.log.iso.md5sum.txt" from the guest OS to the Linux host, the VFAT directory contained filenames "pebuilder.iso86.zip" (having the size of the ISO image), and "pebuilder.logmd5sum.txt" (having the size of the pebuilder.log" file). Again, the this corruption was not detectable from the guest OS.
Finally, I mounted the guest OS disk image using Linux loop device. Copying the ISO files from the NTFS file system using this method was successful. Using PuTTY's sftp also worked.
I hope this report is helpful. I can provided more information if it would be valuable. But, this was frustratingly easy to reproduce. I am willing to help in any way. |
Binary package hint: kvm
KVM Version: 1:72+dfsg-1ubuntu6
QEMU Version: 0.9.1-5ubuntu3
Description: Ubuntu 8.10
Release: 8.10
File Data and Filename corruption occur when copying large files to a Virtual FAT (VFAT) drive. I noticed this when copying ISO images between 150MB and 200MB from WindowsXP guest to the Linux host. These ISO images would not boot. Suspecting corruption, I confirmed MD5 hash values of guest and host copies of these ISO images were different. (The guest OS calculated the correct hashes for files on the VFAT drive, but the files available to the host were corrupted.)
Also, filename corruption also occurred. For example, the VFAT directory on the host contained the file "pebuilder3110a.zip". After "exporting" files named "pebuilder.iso", "pebuilder.log", and "pebuilder.log.iso.md5sum.txt" from the guest OS to the Linux host, the VFAT directory contained filenames "pebuilder.iso86.zip" (having the size of the ISO image), and "pebuilder.logmd5sum.txt" (having the size of the pebuilder.log" file). Again, this corruption was not detectable from the guest OS.
Finally, I mounted the guest OS disk image using Linux loop device. Copying the ISO files from the NTFS file system using this method was successful. Using PuTTY's sftp also worked.
To be clear, this corruption was observed when using both KVM and QEMU.
I hope this report is helpful. I can provided more information if it would be valuable. But, this was frustratingly easy to reproduce. I am willing to help in any way.
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