Re: replaced all drives in RAID-10 array with larger drives -> failing to correctly extend array to use new/add'l space.

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

Hi,

在 2025/01/30 0:12, pgnd 写道:
>                      Layout : far=2
>                  Chunk Size : 512K

I assume you created the array with layout=f2, and this layout doesn't
support resize. mdadm in my VM print the error message:

[root@fedora ~]# mdadm --grow /dev/md0 --size=max
mdadm: failed to write '0' to '/sys/block/md0/md//component_size' 
(Invalid argument)
mdadm: Cannot set device size for /dev/md0: Invalid argument

The error is returned from kernel:

static int raid10_resize(struct mddev *mddev, sector_t sectors)
{
        /* Resize of 'far' arrays is not supported.
        ┊* For 'near' and 'offset' arrays we can set the
        ┊* number of sectors used to be an appropriate multiple
        ┊* of the chunk size.
        ┊* For 'offset', this is far_copies*chunksize.
        ┊* For 'near' the multiplier is the LCM of
        ┊* near_copies and raid_disks.
        ┊* So if far_copies > 1 && !far_offset, fail.
        ┊* Else find LCM(raid_disks, near_copy)*far_copies and
        ┊* multiply by chunk_size.  Then round to this number.
        ┊* This is mostly done by raid10_size()
        ┊*/
        if (conf->geo.far_copies > 1 && !conf->geo.far_offset)
                return -EINVAL;

Thanks,
Kuai