Parted reports that the first block of the disk is free, even if it is occupied by the partition table.

--- libvirt-0.6.4.patches/src/storage_backend_disk.c 2009-06-23 18:17:19.039168000 +0200 +++ libvirt-0.6.4/src/storage_backend_disk.c 2009-06-23 18:17:10.324936000 +0200 @@ -36,6 +36,8 @@ #define PARTHELPER BINDIR "/libvirt_parthelper" +#define SECTOR_SIZE 512 + /* Map partition types to internal enum */ static int virStorageBackendDiskMapPartitionType(const char* partType) @@ -214,6 +216,11 @@ virStorageBackendDiskMakeFreeExtent(virC &dev->freeExtents[dev->nfreeExtent].end) < 0) return -1; /* Don't bother to re-alloc freeExtents - it'll be free'd shortly */ + /* first block reported as free, even if it is not */ + if (dev->freeExtents[dev->nfreeExtent].start == 0) { + dev->freeExtents[dev->nfreeExtent].start = SECTOR_SIZE; + } + pool->def->available += (dev->freeExtents[dev->nfreeExtent].end - dev->freeExtents[dev->nfreeExtent].start);