[Qemu-devel] cgroup blkio.weight or blkio.weight_device has no effect on qemu

2016-01-20 Thread lihuiba
Hi folks, Could you enlighten me how to achieve proportional IO sharing by using cgroup, instead of qemu's io-throttling? My qemu config is like: -drive file=$DISKFILe,if=none,format=qcow2,cache=none,aio=native -device virtio-blk-pci... Test command inside vm is like: dd if=/dev/vdc

Re: [Qemu-devel] qcow2 snapshot + resize

2016-01-18 Thread lihuiba
>I guess the only thing that would need to implement something new is >qcow2_snapshot_goto(), which currently refuses to load a snapshot that >has a different disk size. >Once this is done, just removing the check in qcow2_truncate() should be >okay. Thanks! I'll see what I can do, later.

Re: [Qemu-devel] qcow2 snapshot + resize

2016-01-05 Thread lihuiba
At 2016-01-05 21:55:56, "Eric Blake" <ebl...@redhat.com> wrote: >On 01/05/2016 05:10 AM, lihuiba wrote: > >>>> In our production environment, we need to extend a qcow2 image with >>>> snapshots in it. > >>> The thing is that one would ne

Re: [Qemu-devel] qcow2 snapshot + resize

2016-01-05 Thread lihuiba
Max, I'll see what I can do, and give you my plan. Thanks! >On 29.12.2015 10:38, lihuiba wrote: >> Hi, >> >> In our production environment, we need to extend a qcow2 image with >> snapshots in it. This feature, however, is not implemented yet. >> >

[Qemu-devel] qcow2 snapshot + resize

2015-12-29 Thread lihuiba
Hi, In our production environment, we need to extend a qcow2 image with snapshots in it. This feature, however, is not implemented yet. So I want to ask, if this feature is under active development? How can I help with this feature? It seems that, this feature is not too difficult as long

[Qemu-devel] when to bdrv_co_flush()?

2014-11-09 Thread lihuiba
Hi, all bdrv_co_flush() will flush all cached data to persistent storage, and I'm wondering whether guest sync() will eventually trigger bdrv_co_flush() be called. Intuitively, guest sync() should trigger bdrv_co_flush() in qemu. But simple grep gave me a negative answer. So I'm wondering why

[Qemu-devel] when to bdrv_co_flush()?

2014-11-09 Thread lihuiba
Hi, all bdrv_co_flush() will flush all cached data to persistent storage, and I'm wondering whether guest sync() will eventually trigger bdrv_co_flush() be called. Intuitively, guest sync() should trigger bdrv_co_flush() in qemu. But simple grep gave me a negative answer. So I'm wondering why

[Qemu-devel] when to bdrv_co_flush()?

2014-11-09 Thread lihuiba
Hi, all bdrv_co_flush() will flush all cached data to persistent storage, and I'm wondering whether guest sync() will eventually trigger bdrv_co_flush() be called. Intuitively, guest sync() should trigger bdrv_co_flush() in qemu. But simple grep gave me a negative answer. So I'm wondering why

[Qemu-devel] guest sync and bdrv_co_flush

2014-11-07 Thread lihuiba
Hi, all I'm a user of qemu/kvm, and I'm wondering some internals of qemu/kvm, so I'd better post it in this developer's mailing list. To be specific, I'm wondering how data is flushed to disk. Intuitively, when the guest issues a SYNCHRONIZE CACHE command in the SCSI layer, qemu/kvm should

Re: [Qemu-devel] extremely low IOPS performance of QCOW2 image format on an SSD RAID1

2014-06-23 Thread lihuiba
, the transform wil be degraded to reading external table, and the performances goes extremely low. At 2014-06-23 11:22:37, Fam Zheng f...@redhat.com wrote: Cc'ing more qcow2 experts. On Mon, 06/23 11:14, lihuiba wrote: Did you prefill the image? Amplification could come from cluster

[Qemu-devel] extremely low IOPS performance of QCOW2 image format on an SSD RAID1

2014-06-22 Thread lihuiba
Hi, all I'm using a qcow2 image stored on a SSD RAID1 (2 x intel S3500), and I'm benchmarking the system using fio. Although the throughput in VM (with KVM and virtio enabled) is acceptable (67% of thoughtput in host), the IOPS performance seems is extremely low only 2% of IOPS in host.

Re: [Qemu-devel] extremely low IOPS performance of QCOW2 image format on an SSD RAID1

2014-06-22 Thread lihuiba
test.qcow2 100G Allocating the blocks in VM: dd if=/dev/zero of=/dev/vdb bs=1M where vdb is the target image. At 2014-06-23 11:01:20, Fam Zheng f...@redhat.com wrote: On Mon, 06/23 10:06, lihuiba wrote: Hi, all I'm using a qcow2 image stored on a SSD RAID1 (2 x intel S3500), and I'm