Re: [qemu-web PATCH v3] Add virtio-blk and virtio-scsi configuration post

[Thomas Huth <thuth@redhat.com>]

On 19/01/2021 15.15, Stefan Hajnoczi wrote:
> The second post in the storage series covers virtio-blk and virtio-scsi.
> It compares the two and offers recommendations that users and tools
> using QEMU can use as a starting point. Graphs are included comparing
> the performance of various options.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> v3:
>   * Mention guest drivers for other operation systems [Thomas]
>   * Reorder virtio-blk/virtio-scsi key points [Thomas]
>   * Mention that virtio-blk is limited to disk emulation and doesn't
>     handle CD-ROM drivers, for example [Thomas]
> v2:
>   * Mention default storage controllers for non-x86 [danpb]
>   * Remove statement about read-only ISO virtio-blk devices, both Rich
>     Jones and Daniel Berrange commented about this at different times so
>     I decided to drop it completely [danpb]
>   * Clarify PCI slot limits and multi-function discussion for virtio-blk
>     [danpb]
>   * Mention multiple virtio-scsi devices for NUMA tuning and that
>     emulated LUNs can be HDDs or CD-ROMs [danpb]
> ---
>   ...021-01-19-virtio-blk-scsi-configuration.md | 117 ++++++++++++++++++
>   screenshots/2020-09-15-scsi-devices.svg       |   1 +
>   screenshots/2020-09-15-virtio-blk-vs-scsi.svg |   1 +
>   3 files changed, 119 insertions(+)
>   create mode 100644 _posts/2021-01-19-virtio-blk-scsi-configuration.md
>   create mode 100644 screenshots/2020-09-15-scsi-devices.svg
>   create mode 100644 screenshots/2020-09-15-virtio-blk-vs-scsi.svg
> 
> diff --git a/_posts/2021-01-19-virtio-blk-scsi-configuration.md b/_posts/2021-01-19-virtio-blk-scsi-configuration.md
> new file mode 100644
> index 0000000..a9c7a35
> --- /dev/null
> +++ b/_posts/2021-01-19-virtio-blk-scsi-configuration.md
> @@ -0,0 +1,117 @@
[...]
> +Virtual machines that require access to many disks can hit limits based on
> +availability of PCI slots, which are under contention with other devices
> +exposed to the guest, such as NICs. For example a typical i440fx machine type
> +default configuration allows for about 28 disks. It is possible to use
> +multi-function devices to pack multiple virtio-blk devies into a single PCI

Thanks!

I've replaced "devies" with "devices" and pushed it to the repo now.

  Thomas