Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-27 Thread Hu Tao
On Tue, Aug 26, 2014 at 11:44:26AM +0100, Stefan Hajnoczi wrote: On Mon, Aug 25, 2014 at 09:35:15AM +0800, Hu Tao wrote: On Fri, Aug 22, 2014 at 12:54:29PM +0200, Kevin Wolf wrote: Am 28.07.2014 um 10:48 hat Hu Tao geschrieben: ping... All the 6 patches have reviewed-by now.

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-25 Thread Richard W.M. Jones
On Mon, Aug 25, 2014 at 01:18:30PM +0800, Hu Tao wrote: On Fri, Aug 22, 2014 at 05:00:08PM +0100, Richard W.M. Jones wrote: What is proposed to be called 'preallocation=falloc' should fall back to other methods (eg. writing random, writing zeroes). It should also be called something more

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-25 Thread Richard W.M. Jones
On Mon, Aug 25, 2014 at 01:18:30PM +0800, Hu Tao wrote: What if user cares about time(writing zeroes or non-zeroes is time-consuming) and wants falloc only sometimes? I think this is the main difference between preallocation=falloc and preallocation=full. Also posix_fallocate in glibc falls

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-25 Thread Hu Tao
On Fri, Aug 22, 2014 at 05:00:08PM +0100, Richard W.M. Jones wrote: On Fri, Aug 22, 2014 at 05:53:22PM +0200, Kevin Wolf wrote: Am 22.08.2014 um 17:34 hat Richard W.M. Jones geschrieben: On Fri, Aug 22, 2014 at 05:22:33PM +0200, Kevin Wolf wrote: It's still useful because it happens to

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-24 Thread Hu Tao
On Fri, Aug 22, 2014 at 12:54:29PM +0200, Kevin Wolf wrote: Am 28.07.2014 um 10:48 hat Hu Tao geschrieben: ping... All the 6 patches have reviewed-by now. Looks mostly good to me, I have only a few minor comments that wouldn't block inclusion but could be addressed in follow-up

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-24 Thread Hu Tao
On Fri, Aug 22, 2014 at 05:00:08PM +0100, Richard W.M. Jones wrote: On Fri, Aug 22, 2014 at 05:53:22PM +0200, Kevin Wolf wrote: Am 22.08.2014 um 17:34 hat Richard W.M. Jones geschrieben: On Fri, Aug 22, 2014 at 05:22:33PM +0200, Kevin Wolf wrote: It's still useful because it happens to

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Richard W.M. Jones
On Mon, Jul 28, 2014 at 04:48:46PM +0800, Hu Tao wrote: ping... All the 6 patches have reviewed-by now. On Fri, Jul 11, 2014 at 02:09:57PM +0800, Hu Tao wrote: This series adds two preallocation mode to qcow2 and raw: Option preallocation=full preallocates disk space for image by

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Daniel P. Berrange
On Fri, Aug 22, 2014 at 01:25:56PM +0100, Richard W.M. Jones wrote: On Mon, Jul 28, 2014 at 04:48:46PM +0800, Hu Tao wrote: ping... All the 6 patches have reviewed-by now. On Fri, Jul 11, 2014 at 02:09:57PM +0800, Hu Tao wrote: This series adds two preallocation mode to qcow2 and

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Kevin Wolf
Am 22.08.2014 um 14:25 hat Richard W.M. Jones geschrieben: On Mon, Jul 28, 2014 at 04:48:46PM +0800, Hu Tao wrote: ping... All the 6 patches have reviewed-by now. On Fri, Jul 11, 2014 at 02:09:57PM +0800, Hu Tao wrote: This series adds two preallocation mode to qcow2 and raw:

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Daniel P. Berrange
On Fri, Aug 22, 2014 at 03:13:31PM +0200, Kevin Wolf wrote: Am 22.08.2014 um 14:25 hat Richard W.M. Jones geschrieben: On Mon, Jul 28, 2014 at 04:48:46PM +0800, Hu Tao wrote: ping... All the 6 patches have reviewed-by now. On Fri, Jul 11, 2014 at 02:09:57PM +0800, Hu Tao

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Kevin Wolf
Am 22.08.2014 um 16:20 hat Daniel P. Berrange geschrieben: On Fri, Aug 22, 2014 at 03:13:31PM +0200, Kevin Wolf wrote: Am 22.08.2014 um 14:25 hat Richard W.M. Jones geschrieben: On Mon, Jul 28, 2014 at 04:48:46PM +0800, Hu Tao wrote: ping... All the 6 patches have

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Richard W.M. Jones
On Fri, Aug 22, 2014 at 05:22:33PM +0200, Kevin Wolf wrote: It's still useful because it happens to reduce the overhead in most implementations and it's a relatively quick operation, but the best way I know of to actually _fully_ preallocate is still writing zeros. Which of the two the user

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Richard W.M. Jones
On Fri, Aug 22, 2014 at 04:34:40PM +0100, Richard W.M. Jones wrote: - really really try as hard as possible to make sure that future allocations will never fail (ie. write random non-zero data to the file) s/will never fail/are not needed and will never fail/ Rich. -- Richard Jones,

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Richard W.M. Jones
On Fri, Aug 22, 2014 at 05:53:22PM +0200, Kevin Wolf wrote: Am 22.08.2014 um 17:34 hat Richard W.M. Jones geschrieben: On Fri, Aug 22, 2014 at 05:22:33PM +0200, Kevin Wolf wrote: It's still useful because it happens to reduce the overhead in most implementations and it's a relatively

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-08-22 Thread Kevin Wolf
Am 22.08.2014 um 17:34 hat Richard W.M. Jones geschrieben: On Fri, Aug 22, 2014 at 05:22:33PM +0200, Kevin Wolf wrote: It's still useful because it happens to reduce the overhead in most implementations and it's a relatively quick operation, but the best way I know of to actually _fully_

Re: [Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-07-28 Thread Hu Tao
ping... All the 6 patches have reviewed-by now. On Fri, Jul 11, 2014 at 02:09:57PM +0800, Hu Tao wrote: This series adds two preallocation mode to qcow2 and raw: Option preallocation=full preallocates disk space for image by writing zeros to disk, this ensures disk space in any cases.

[Qemu-devel] [PATCH v12 0/6] qcow2, raw: add preallocation=full and preallocation=falloc

2014-07-11 Thread Hu Tao
This series adds two preallocation mode to qcow2 and raw: Option preallocation=full preallocates disk space for image by writing zeros to disk, this ensures disk space in any cases. Option preallocation=falloc preallocates disk space by calling posix_fallocate(). This is faster than