Re: [PATCH v2 29/37] guestfs: Configure how many extra drives to provision

[Daniel Gomez <da.gomez@kernel.org>]

On 02/09/2025 15.54, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> Some workflows create several guests but use only one or two extra
> storage drives per guest. Enable configurations that reduce the
> amount of storage allocated per guest to conserve local persistent
> storage space on the host.
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

This should allow workflows to specify the nr of drives needed, right?

Looks great optimization, thanks!

Reviewed-by: Daniel Gomez <da.gomez@samsung.com>

> ---
>  kconfigs/Kconfig.libvirt                      | 45 +++++++++++++++++++
>  .../roles/gen_nodes/templates/gen_drives.j2   |  8 ++--
>  .../roles/guestfs/tasks/bringup/main.yml      |  2 +-
>  3 files changed, 50 insertions(+), 5 deletions(-)
> 
> diff --git a/kconfigs/Kconfig.libvirt b/kconfigs/Kconfig.libvirt
> index 7fe231668229..961276ccc1b1 100644
> --- a/kconfigs/Kconfig.libvirt
> +++ b/kconfigs/Kconfig.libvirt
> @@ -556,6 +556,51 @@ config LIBVIRT_HOST_PASSTHROUGH
>  	      --pre 'make -s mrproper defconfig' \
>  	    \-- make -s -j$(nproc) bzImage
>  
> +choice
> +	prompt "Libvirt extra storage drive count"
> +	default LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_4

I see we are defaulting to what we had. So it's up to the user or defconfig to
leverage this.

> +	help
> +	  This option selects the number of extra storage drives to
> +	  provision for each libvirt guest. Reduce this number to
> +	  conserve local host storage capacity, if your workflows do
> +	  not use all the extra drives.
> +
> +config LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_0
> +	bool "0"
> +	help
> +	  Provision no extra storage drives per guest.

Curious, any reason to have a menu/choice instead of int?


> +
> +config LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_1
> +	bool "1"
> +	help
> +	  Provision one extra storage drive per guest.
> +
> +config LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_2
> +	bool "2"
> +	help
> +	  Provision two extra storage drives per guest.
> +
> +config LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_3
> +	bool "3"
> +	help
> +	  Provision three extra storage drives per guest.
> +
> +config LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_4
> +	bool "4"
> +	help
> +	  Provision four extra storages drive per guest.
> +
> +endchoice
> +
> +config LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT
> +	int
> +	output yaml
> +	default 0 if LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_0
> +	default 1 if LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_1
> +	default 2 if LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_2
> +	default 3 if LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_3
> +	default 4 if LIBVIRT_EXTRA_STORAGE_DRIVE_COUNT_4
> +
>  choice
>  	prompt "Libvirt extra storage driver to use"
>  	default LIBVIRT_EXTRA_STORAGE_DRIVE_VIRTIO
> diff --git a/playbooks/roles/gen_nodes/templates/gen_drives.j2 b/playbooks/roles/gen_nodes/templates/gen_drives.j2
> index 2de13da4ab8e..1040c0e19d84 100644
> --- a/playbooks/roles/gen_nodes/templates/gen_drives.j2
> +++ b/playbooks/roles/gen_nodes/templates/gen_drives.j2
> @@ -1,6 +1,6 @@
>  {% import './templates/drives.j2' as drives %}
>  {% if libvirt_extra_storage_drive_ide %}
> -{{ drives.gen_drive_ide(4,
> +{{ drives.gen_drive_ide(libvirt_extra_storage_drive_count,
>  			kdevops_storage_pool_path,
>  			hostname,
>  			libvirt_extra_drive_format,
> @@ -18,7 +18,7 @@
>  				    libvirt_extra_storage_aio_cache_mode,
>  				    kdevops_storage_pool_path) }}
>  {% else %}
> -{{ drives.gen_drive_virtio(4,
> +{{ drives.gen_drive_virtio(libvirt_extra_storage_drive_count,
>                             kdevops_storage_pool_path,
>                             hostname,
>                             libvirt_extra_drive_format,
> @@ -28,7 +28,7 @@
>                             libvirt_extra_storage_virtio_physical_block_size) }}
>  {% endif %}
>  {% elif libvirt_extra_storage_drive_scsi %}
> -{{ drives.gen_drive_scsi(4,
> +{{ drives.gen_drive_scsi(libvirt_extra_storage_drive_count,
>                           kdevops_storage_pool_path,
>                           hostname,
>                           libvirt_extra_drive_format,
> @@ -46,7 +46,7 @@
>  				  libvirt_extra_storage_aio_cache_mode,
>  				  kdevops_storage_pool_path) }}
>  {% else %}
> -{{ drives.gen_drive_nvme(4,
> +{{ drives.gen_drive_nvme(libvirt_extra_storage_drive_count,
>  			 kdevops_storage_pool_path,
>  			 hostname,
>  			 libvirt_extra_drive_format,
> diff --git a/playbooks/roles/guestfs/tasks/bringup/main.yml b/playbooks/roles/guestfs/tasks/bringup/main.yml
> index bd9f52603a3b..3fd677ff4659 100644
> --- a/playbooks/roles/guestfs/tasks/bringup/main.yml
> +++ b/playbooks/roles/guestfs/tasks/bringup/main.yml
> @@ -102,7 +102,7 @@
>          path: "{{ storagedir }}/{{ inventory_hostname }}/extra{{ item }}.{{ libvirt_extra_drive_format }}"
>        ansible.builtin.include_tasks:
>          file: "{{ role_path }}/tasks/bringup/extra-disks.yml"
> -      loop: "{{ range(0, 4) | list }}"
> +      loop: "{{ range(0, libvirt_extra_storage_drive_count) | list }}"
>        when:
>          - not libvirt_enable_largeio|bool
>