https://bugzilla.redhat.com/show_bug.cgi?id=1430679 As it turns out some file headers (e.g. ext4) may be larger/longer than the 512 bytes of zeros being written prior to a pvcreate, so let's write out 2048 bytes similar to how the pvcreate sources would peek at the first 4 sectors of the device. Make sure there is at enough bytes on the device to clear before doing doing the clear - just to be sure. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- src/storage/storage_backend_logical.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c index 29d63b1..9ca6fd4 100644 --- a/src/storage/storage_backend_logical.c +++ b/src/storage/storage_backend_logical.c @@ -93,7 +93,8 @@ static int virStorageBackendLogicalInitializeDevice(const char *path) { int fd = -1; - char zeros[PV_BLANK_SECTOR_SIZE] = {0}; + char zeros[4 * PV_BLANK_SECTOR_SIZE] = {0}; + off_t size; int ret = -1; virCommandPtr pvcmd = NULL; @@ -107,6 +108,25 @@ virStorageBackendLogicalInitializeDevice(const char *path) return -1; } + if ((size = lseek(fd, 0, SEEK_END)) == (off_t)-1) { + virReportSystemError(errno, + _("failed to seek to end of %s"), path); + goto cleanup; + } + + if (size < 4 * PV_BLANK_SECTOR_SIZE) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("cannot initialize '%s' detected size='%lu' less " + "than minimum required='%d"), + path, size, 4 * PV_BLANK_SECTOR_SIZE); + goto cleanup; + } + if ((size = lseek(fd, 0, SEEK_SET)) == (off_t)-1) { + virReportSystemError(errno, + _("failed to seek to start of %s"), path); + goto cleanup; + } + if (safewrite(fd, zeros, sizeof(zeros)) < 0) { virReportSystemError(errno, _("cannot clear device header of '%s'"), path); -- 2.9.3