Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, Apr 24, 2017 at 8:36 PM, Fam Zheng wrote: > On Mon, 04/24 20:26, 858585 jemmy wrote: >> > 2) qcow2 with cluster_size = 512 is probably too uncommon to be optimized >> > for. >> if culster_size is very small, should disable metadata check default? >> > > No, I don't think

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, 04/24 20:26, 858585 jemmy wrote: > > 2) qcow2 with cluster_size = 512 is probably too uncommon to be optimized > > for. > if culster_size is very small, should disable metadata check default? > No, I don't think it's worth the inconsistent behavior. People who want performance shouldn't

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, Apr 24, 2017 at 8:19 PM, Fam Zheng wrote: > On Mon, 04/24 20:09, Fam Zheng wrote: >> It's a separate problem. > > To be specific: > > 1) there is an option "overlap-check" that one can use to > disable the costly metadata check; yes, i will disable metadata check, and

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, 04/24 20:09, Fam Zheng wrote: > It's a separate problem. To be specific: 1) there is an option "overlap-check" that one can use to disable the costly metadata check; 2) qcow2 with cluster_size = 512 is probably too uncommon to be optimized for. Both are irrelevant to why and how this

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, Apr 24, 2017 at 8:09 PM, Fam Zheng wrote: > On Mon, 04/24 19:54, 858585 jemmy wrote: >> On Mon, Apr 24, 2017 at 3:40 PM, 858585 jemmy wrote: >> > On Mon, Apr 17, 2017 at 12:00 PM, 858585 jemmy >> > wrote: >> >> On Mon, Apr

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, 04/24 19:54, 858585 jemmy wrote: > On Mon, Apr 24, 2017 at 3:40 PM, 858585 jemmy wrote: > > On Mon, Apr 17, 2017 at 12:00 PM, 858585 jemmy > > wrote: > >> On Mon, Apr 17, 2017 at 11:49 AM, Fam Zheng wrote: > >>> On Fri,

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, Apr 24, 2017 at 3:40 PM, 858585 jemmy wrote: > On Mon, Apr 17, 2017 at 12:00 PM, 858585 jemmy wrote: >> On Mon, Apr 17, 2017 at 11:49 AM, Fam Zheng wrote: >>> On Fri, 04/14 14:30, 858585 jemmy wrote: Do you know some

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, Apr 17, 2017 at 12:00 PM, 858585 jemmy wrote: > On Mon, Apr 17, 2017 at 11:49 AM, Fam Zheng wrote: >> On Fri, 04/14 14:30, 858585 jemmy wrote: >>> Do you know some other format which have very small cluster size? >> >> 64k is the default cluster

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Mon, Apr 17, 2017 at 11:49 AM, Fam Zheng wrote: > On Fri, 04/14 14:30, 858585 jemmy wrote: >> Do you know some other format which have very small cluster size? > > 64k is the default cluster size for qcow2 but it can be configured at image > creation time, as 512 bytes, for

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Fri, 04/14 14:30, 858585 jemmy wrote: > Do you know some other format which have very small cluster size? 64k is the default cluster size for qcow2 but it can be configured at image creation time, as 512 bytes, for example: $ qemu-img create -f qcow2 test.qcow2 -o cluster_size=512 1G Fam

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Fri, Apr 14, 2017 at 2:00 PM, Fam Zheng wrote: > On Thu, 04/13 10:34, jemmy858...@gmail.com wrote: >> From: Lidong Chen >> >> BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default, >> this may cause the qcow2 file size to be bigger after

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Thu, 04/13 10:34, jemmy858...@gmail.com wrote: > From: Lidong Chen > > BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default, > this may cause the qcow2 file size to be bigger after migration. > This patch checks each cluster, using blk_pwrite_zeroes for each

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Thu, Apr 13, 2017 at 10:16 PM, Stefan Hajnoczi wrote: > On Thu, Apr 13, 2017 at 10:34:28AM +0800, jemmy858...@gmail.com wrote: >> From: Lidong Chen >> >> BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default, >> this may cause the qcow2

Re: [Qemu-devel] [PATCH v6] migration/block: use blk_pwrite_zeroes for each zero cluster

On Thu, Apr 13, 2017 at 10:34:28AM +0800, jemmy858...@gmail.com wrote: > From: Lidong Chen > > BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default, > this may cause the qcow2 file size to be bigger after migration. > This patch checks each cluster, using