Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Eric Blake
On 07/18/2013 01:13 PM, Ian Main wrote: > On Thu, Jul 18, 2013 at 12:56:51PM -0600, Eric Blake wrote: >> On 07/18/2013 12:47 PM, Ian Main wrote: >>> qcow2 supports backing files so it makes sense to default to qcow2 >>> for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing >>> drive

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Ian Main
On Thu, Jul 18, 2013 at 12:56:51PM -0600, Eric Blake wrote: > On 07/18/2013 12:47 PM, Ian Main wrote: > > qcow2 supports backing files so it makes sense to default to qcow2 > > for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing > > drive and export it via nbd. Defaulting FULL and

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Eric Blake
On 07/18/2013 12:47 PM, Ian Main wrote: > qcow2 supports backing files so it makes sense to default to qcow2 > for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing > drive and export it via nbd. Defaulting FULL and TOP to SYNC_MODE_NONE > breaks tests but that could be fixed if we

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Eric Blake
On 07/18/2013 12:03 PM, Ian Main wrote: >> >> Or we could simplify life by making 'format' mandatory for drive-backup; >> it was optional for 'drive-mirror' due to incremental implementation, >> but for 'drive-backup', we still have the opportunity to do things right >> from the first release. > >

[Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Ian Main
qcow2 supports backing files so it makes sense to default to qcow2 for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing drive and export it via nbd. Defaulting FULL and TOP to SYNC_MODE_NONE breaks tests but that could be fixed if we wanted it. Signed-off-by: Ian Main --- blockd

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Ian Main
On Thu, Jul 18, 2013 at 11:27:21AM -0600, Eric Blake wrote: > On 07/17/2013 02:04 PM, Ian Main wrote: > > qcow2 supports backing files so it makes sense to default to qcow2 > > for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing > > drive and export it via nbd. Defaulting FULL and

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Ian Main
On Thu, Jul 18, 2013 at 11:32:52AM -0600, Eric Blake wrote: > On 07/18/2013 11:27 AM, Eric Blake wrote: > > >> if (!has_format) { > >> -format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : > >> bs->drv->format_name; > >> +format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : "qcow2"

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Eric Blake
On 07/18/2013 11:27 AM, Eric Blake wrote: >> if (!has_format) { >> -format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : >> bs->drv->format_name; >> +format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : "qcow2"; > > Is this the right thing to do? Or should we do: > > if (!has_fo

Re: [Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-18 Thread Eric Blake
On 07/17/2013 02:04 PM, Ian Main wrote: > qcow2 supports backing files so it makes sense to default to qcow2 > for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing > drive and export it via nbd. Defaulting FULL and TOP to SYNC_MODE_NONE > breaks tests but that could be fixed if we

[Qemu-devel] [PATCH V4 4/4] Change default to qcow2 for sync mode none.

2013-07-17 Thread Ian Main
qcow2 supports backing files so it makes sense to default to qcow2 for MIRROR_SYNC_MODE_NONE so that we can use the source as a backing drive and export it via nbd. Defaulting FULL and TOP to SYNC_MODE_NONE breaks tests but that could be fixed if we wanted it. Signed-off-by: Ian Main --- blockd