Hi guys. I have a bizarre problem. Hopefully someone will provide some insight. I would like to wrap my NTFS Windows XP partition into a virtual hard disk for use with virtualization tools such as XEN or KVM. In order to turn a partition into a virtual hard disk I must prepend enough space at the beginning to allow space for the MBR and the partition table. The idea I have is to create a little partition (/dev/sda5) on the tail of my hard drive and use the md driver in linear mode to prepend this to the NTFS partition (/dev/sda1). The resulting md device should appear to Windows as a real hard drive, with its own MBR and partition table. I am using the following command to create the md device: mdadm --build /dev/md0 -l linear -n2 /dev/sda5 /dev/sda1 The md device gets created properly and can be used with fdisk to create a partition table. However, the size of the md device, as reported by fdisk, does not match the sum of the size of the constituent block devices, always as reported by fdisk. Here is a table showing the start and end sectors and the computed and reported sizes of the two constituent partitions, sda1 and sda5, and of the md device. block dev reported size start end computed size delta /dev/sda1 241797953 63 241798015 241797953 0 /dev/sda5 16002 491797908 491813909 16002 0 /dev/md0 241813888 241813955 -67 As you can see the computed size is 67 sectors less than the reported size. What happened to those sectors? They are surely not used to store superblocks, as the --build command does not create superblocks. If they are used for the md driver's magic, do they all come from the first device of the array or are they distributed on both? All in all, how safe (or unsafe) is my approach to virtualizing Windows XP on my Linux box? Thank you in advance for any help you can provide. Alex -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
