Re: [libvirt] [PATCH] rbd: Use RBD format 2 by default when creating images.

We used to look at the librbd code version and depending on that we would invoke rbd_create3() or rbd_create(). Since librbd version 0.67.9 we can however tell RBD that it should create rbd format 2 images even if we invoke rbd_create(). The less options we pass to librbd, the more we can lean on the sane defaults it uses. For rbd_create3() we had things like the stripe count and unit hardcoded in libvirt and that might cause problems down the road. Signed-off-by: Wido den Hollander <wido(a)widodh.nl&gt; --- src/storage/storage_backend_rbd.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c index 8e8d7a7..936ad18 100644 --- a/src/storage/storage_backend_rbd.c +++ b/src/storage/storage_backend_rbd.c @@ -66,6 +66,7 @@ static int virStorageBackendRBDOpenRADOSConn(virStorageBackendRBDStatePtr ptr, const char *client_mount_timeout = "30"; const char *mon_op_timeout = "30"; const char *osd_op_timeout = "30"; + const char *rbd_default_format = "2"; if (authdef) { VIR_DEBUG("Using cephx authorization, username: %s", authdef->username); @@ -211,6 +212,14 @@ static int virStorageBackendRBDOpenRADOSConn(virStorageBackendRBDStatePtr ptr, VIR_DEBUG("Setting RADOS option rados_osd_op_timeout to %s", osd_op_timeout); rados_conf_set(ptr->cluster, "rados_osd_op_timeout", osd_op_timeout); + /* + * Librbd supports creating RBD format 2 images. We no longer have to invoke + * rbd_create3(), we can tell librbd to default to format 2. + * This leaves us to simply use rbd_create() and use the default behavior of librbd + */ + VIR_DEBUG("Setting RADOS option rbd_default_format to %s", rbd_default_format); + rados_conf_set(ptr->cluster, "rbd_default_format", rbd_default_format); +

ptr->starttime = time(0); r = rados_connect(ptr->cluster); if (r < 0) { @@ -475,16 +484,7 @@ static int virStorageBackendRBDCreateImage(rados_ioctx_t io, char *name, long capacity) { int order = 0; -#if LIBRBD_VERSION_CODE > 260 - uint64_t features = 3; - uint64_t stripe_count = 1; - uint64_t stripe_unit = 4194304; - - if (rbd_create3(io, name, capacity, features, &order, - stripe_unit, stripe_count) < 0) { -#else if (rbd_create(io, name, capacity, &order) < 0) { -#endif

return -1; }