Re: Where to define multiple volumes sizes in one MTD rootfs partition?

[JH <jupiter.hce@gmail.com>]

Hi,

Sorry, if it is not right the mailing list to ask helps for multiple
volumes in a single ubi0 instance, any advice please?

Thank you.

Kind regards,

- jh

On 10/11/19, JH <jupiter.hce@gmail.com> wrote:
> On 10/5/19, Richard Weinberger <richard.weinberger@gmail.com> wrote:
>> On Sat, Oct 5, 2019 at 2:51 AM JH <jupiter.hce@gmail.com> wrote:
>>> Recently, one of my device is broken failed to boot up, I still don't
>>> know what was the cause by hardware problem or software, to be
>>> precaution in the future meltdown, I am going to separate all writing
>>> data from ubi0 to to another ubi volume ubi1, to keep the rootfs in
>>> ubi0 read only. How can I define the ubi0 volume size to 160 MB and
>>> the ubi1 volume size to 30 MB?
>>
>> Don't setup multiple UBI instances on the same chip.
>> The wear leveling domain should be as large as possible.
>>
>> If you want to have multiple UBIFS filesystems, just create more UBI
>> volumes.
>
> Hmm, wandering for several days how to do it, reading lots of
> documents, still not clear how could I make that work, let's say I
> have following a volume configure file:
>
> $ cat volume.conf
>
> [kernel-volume]
> mode=ubi
> image=zImage
> vol_id=1
> vol_size=10MiB
> vol_type=static
> vol_name=kernel
>
> [rootfs-volume]
> mode=ubi
> image=rootfs_data
> vol_id=2
> vol_size=110MiB
> vol_type=static
> vol_name=rootfs
>
> [data-volume]
> mode=ubi
> image=rootfs_data
> vol_id=3
> vol_size=10MiB
> vol_type=dynamic
> vol_name=data
> vol_flags=autoresize
>
> $ ubinize -o rootfs.img -p 130MiB -m 512 -s 256 volume.conf
>
> $ ubidetach -p /dev/mtd5
> $ ubiformat /dev/mtd5 -y
> $ ubiattach -m 5
> $ ubimkvol /dev/ubi0 -s 130MiB -N rootfs_data
>
> $ mount -t ubifs ubi0:rootfs_data /mnt
>
> If I have a single ubi0 rootfs in /dev/mtd5, I can set
> "root=ubi0:rootfs_data rw ubi.mtd=5,2048  noinitrd rootfstype=ubifs
> mem=256M rootwait=1"
>
> $ tar zxvf yocto-image-rootfs.tar.gz -C /mnt
>
> It can boot from the a single rootfs volume.
>
> But for multiple volumes in ubi0, I lost completely, how can it boot
> from volume configure file with multiple volumes? Where the
> volume.conf should be placed in Linux rootfs, in "/"? If it is correct
> to copy volume.conf to /mnt (the "/"), how will it boot from NAND with
> multiple volumes? That is most confusing parts, I could not see any
> clear examples and statements in documents, appreciate kindly advice.
>
> Thank you very much Richard.
>
> Kind regards,
>
> - jh
>

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