When creating preallocated large raw files opening them with O_DSYNC prevents long delays in reading because cache pages can be immediately reused without writing them on a disk first. Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; --- src/storage/storage_backend.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c index e79294a..8aab9ab 100644 --- a/src/storage/storage_backend.c +++ b/src/storage/storage_backend.c @@ -301,7 +301,7 @@ virStorageBackendCreateRaw(virConnectPtr conn, goto cleanup; } - if ((fd = open(vol->target.path, O_RDWR | O_EXCL)) < 0) { + if ((fd = open(vol->target.path, O_RDWR | O_EXCL | O_DSYNC)) < 0) { virReportSystemError(conn, errno, _("cannot open new path '%s'"), vol->target.path); --