Re: [isar-cip-core][RFC][PATCH 10/10] Enable A/B snapshot for /var on x86 and qemu-arm64

MOESSBAUER, Felix
2025-01-30T23:43:27Z

On Thu, 2025-01-30 at 10:39 +0100, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> Other targets still need testing, some even kernel config tuning.

Hi,

do we have a target that uses docker / podman? The containers are
usually stored on /var and this is not necessarily compatible with
BTRFS OOTB. In general, docker does not play nicely with a COW
filesystem. That's one of the reasons the docker-btrfs driver was
invented. However, I'm unsure how that works together with our A/B
logic.

For details, please also see
https://docs.docker.com/engine/storage/drivers/btrfs-driver/

Best regards,
Felix

>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  conf/machine/qemu-amd64.conf | 5 ++++-
>  conf/machine/qemu-arm64.conf | 5 ++++-
>  conf/machine/x86-uefi.conf   | 5 +++--
>  3 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/conf/machine/qemu-amd64.conf b/conf/machine/qemu-
> amd64.conf
> index d7866468..5244c86a 100644
> --- a/conf/machine/qemu-amd64.conf
> +++ b/conf/machine/qemu-amd64.conf
> @@ -1,7 +1,7 @@
>  #
>  # CIP Core, generic profile
>  #
> -# Copyright (c) Siemens AG, 2019-2024
> +# Copyright (c) Siemens AG, 2019-2025
>  #
>  # SPDX-License-Identifier: MIT
>  #
> @@ -11,3 +11,6 @@ DISTRO_ARCH = "amd64"
>  IMAGE_FSTYPES ?= "ext4"
>  USE_CIP_KERNEL_CONFIG = "1"
>  KERNEL_DEFCONFIG = "cip-kernel-
> config/${KERNEL_DEFCONFIG_VERSION}/x86/cip_merged_defconfig"
> +
> +IMAGER_INSTALL:wic += "btrfs-progs"
> +VAR_FS_TYPE = "btrfs"
> diff --git a/conf/machine/qemu-arm64.conf b/conf/machine/qemu-
> arm64.conf
> index a2c5e53e..49323a11 100644
> --- a/conf/machine/qemu-arm64.conf
> +++ b/conf/machine/qemu-arm64.conf
> @@ -1,7 +1,7 @@
>  #
>  # CIP Core, generic profile
>  #
> -# Copyright (c) Siemens AG, 2019
> +# Copyright (c) Siemens AG, 2019-2025
>  #
>  # SPDX-License-Identifier: MIT
>  #
> @@ -16,3 +16,6 @@ KERNEL_DEFCONFIG ?= "cip-kernel-
> config/${KERNEL_DEFCONFIG_VERSION}/arm64/cip_mer
>  WDOG_TIMEOUT = "0"
>
>  PREFERRED_PROVIDER_u-boot-${MACHINE} = "u-boot-qemu-arm64"
> +
> +IMAGER_INSTALL:wic += "btrfs-progs"
> +VAR_FS_TYPE = "btrfs"
> diff --git a/conf/machine/x86-uefi.conf b/conf/machine/x86-uefi.conf
> index 33f82b16..0a69ea82 100644
> --- a/conf/machine/x86-uefi.conf
> +++ b/conf/machine/x86-uefi.conf
> @@ -1,7 +1,7 @@
>  #
>  # CIP Core, generic profile
>  #
> -# Copyright (c) Siemens AG, 2019-2024
> +# Copyright (c) Siemens AG, 2019-2025
>  #
>  # SPDX-License-Identifier: MIT
>  #
> @@ -10,6 +10,7 @@ DISTRO_ARCH = "amd64"
>
>  IMAGE_FSTYPES ?= "wic"
>  WKS_FILE ?= "x86_64-generic.wks"
> -IMAGER_INSTALL:wic += "${GRUB_BOOTLOADER_INSTALL}"
> +IMAGER_INSTALL:wic += "${GRUB_BOOTLOADER_INSTALL} btrfs-progs"
> +VAR_FS_TYPE = "btrfs"
>  USE_CIP_KERNEL_CONFIG = "1"
>  KERNEL_DEFCONFIG = "cip-kernel-
> config/${KERNEL_DEFCONFIG_VERSION}/x86/cip_merged_defconfig"

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