I've just had a look at this patch again and I see a problem. You always offset by 63 sectors, despite the out of ubuntu-vmbuilder saying (see attached output) that the CHS geometry used was */4/32. You are offsetting by 63 sectors, so that's not a a cyl boundary.
More seriously, if this image goes via iSCSI, you ENSURE no read is 4k aligned, which is very bad performance wise. I suggest offsetting by 64 cylinders, not 63. Alex sfdisk -l -uS ./ubuntu-lucid-amd64-httpmetadata.img Disk ./ubuntu-lucid-amd64-httpmetadata.img: cannot get geometry Disk ./ubuntu-lucid-amd64-httpmetadata.img: 2610 cylinders, 255 heads, 63 sectors/track Warning: The partition table looks like it was made for C/H/S=*/4/32 (instead of 2610/255/63). For this listing I'll assume that geometry. Units = sectors of 512 bytes, counting from 0 Device Boot Start End #sectors Id System ./ubuntu-lucid-amd64-httpmetadata.img1 1 39996093 39996093 83 Linux ./ubuntu-lucid-amd64-httpmetadata.img2 0 - 0 0 Empty ./ubuntu-lucid-amd64-httpmetadata.img3 0 - 0 0 Empty ./ubuntu-lucid-amd64-httpmetadata.img4 0 - 0 0 Empty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/578199 Title: ubuntu-vm-builder builds images with no post-MBR gap -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
