Re: [PATCH] Add '--nodes' option in GROW mode

[Jes Sorensen <Jes.Sorensen@redhat.com>]

zhilong <zlliu@suse.com> writes:
> Bug description:
> # mdadm -Cv /dev/md0 --bitmap=clustered -l1 -n2 /dev/sdd /dev/sdb
> --nodes=6 --assume-clean
> # mdadm --grow /dev/md0 --bitmap=none
> # mdadm --grow /dev/md0 --bitmap=clustered
>     -> cluster nodes would be changed to 4, here is my method to
> resolve it.
> # mdadm --grow /dev/md0 --bitmap=clustered --nodes=6
>
> Patch:
>
> Cluster nodes is set 4 as default when switch bitmap from
> none to clustered under GROW mode, so add '--nodes'
> option in GROW mode.
>
> Signed-off-by: Zhilong Liu <zlliu@suse.com>
> ---
>  mdadm.c | 1 +
>  1 file changed, 1 insertion(+)

Hi,

I have a question about this, since I simply do not have the knowledge
about clustering to judge this approach.

If you remove the bitmap, does that 'uncluster' the array? If not,
shouldn't mdadm be fixed to not set #nodes to 4 when adding a clustered
bitmap, if a number of cluster nodes is already present?

Thanks,
Jes

>
> diff --git a/mdadm.c b/mdadm.c
> index 51e16f3..b542b8c 100644
> --- a/mdadm.c
> +++ b/mdadm.c
> @@ -592,6 +592,7 @@ int main(int argc, char *argv[])
>              ident.raid_disks = s.raiddisks;
>              continue;
>          case O(ASSEMBLE, Nodes):
> +        case O(GROW, Nodes):
>          case O(CREATE, Nodes):
>              c.nodes = parse_num(optarg);
>              if (c.nodes <= 0) {