On Fri, 2014-06-20 at 15:07 -0600, Jim Fehlig wrote:
The libxl driver currently sets the disk backend to LIBXL_DISK_BACKEND_TAP when <driver name='file'> is specified in the <disk> config. qdisk should be prefered with this configuration, otherwise existing configuration such as the following, which worked with the old Xen driver, will not work with the libxl driver
OOI why not let libxl pick the most appropriate backend for (most of) these alternatives?
<disk type='file' device='cdrom'> <driver name='file'/> <source file='/path/to/some/iso'/> <target dev='hdc' bus='ide'/> <readonly/> </disk>
In addition, tap performs poorly compared to qdisk.
Signed-off-by: Jim Fehlig <jfehlig@suse.com> --- src/libxl/libxl_conf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index fdbb522..4b6b5c0 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -796,7 +796,7 @@ libxlMakeDisk(virDomainDiskDefPtr l_disk, libxl_device_disk *x_disk) return -1; } x_disk->format = LIBXL_DISK_FORMAT_RAW; - x_disk->backend = LIBXL_DISK_BACKEND_TAP; + x_disk->backend = LIBXL_DISK_BACKEND_QDISK; } else if (STREQ(driver, "phy")) { if (format != VIR_STORAGE_FILE_NONE && format != VIR_STORAGE_FILE_RAW) {