Re: [PATCH -v2 1/1] mdadm/test: Add one test case for raid5 reshape

[Zhilong Liu <zlliu@suse.com>]

On 07/17/2017 05:27 PM, Xiao Ni wrote:
> This case trys to allow raid5 reshape to use backwards direction.
> It changes chunksize after reshape and stop the raid. Then start
> the raid again.
>
> Signed-off-by: Xiao Ni <xni@redhat.com>
> ---
>   tests/02r5grow | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/tests/02r5grow b/tests/02r5grow
> index 386e82e..64c5599 100644
> --- a/tests/02r5grow
> +++ b/tests/02r5grow
> @@ -34,3 +34,16 @@ check nosync
>   sh tests/testdev $md0 3 $[size/2] 128
>   
>   mdadm -S $md0
> +
> +# create a raid5 array and change the chunk
> +mdadm -CR $md0 --level raid5 --metadata=1.1 --chunk=32 --raid-disks 3 --size $[size/2] $dev1 $dev2 $dev3
> +check wait
> +check state UUU
> +

Hi,
    Just my opinion, it should check the chunk-size properly if you 
wanna test 'chunk'.
    Maybe can do following three things in a function.

 From sysfs:
new_size=$(cat /sys/block/md0/md/chunk_size)
if [ "$(expr 32 \* 1024)" -eq "$new_size" ]; then
...
fi

 From procfs:
# cat /proc/mdstat  | awk -F',' '/chunk/{print $2}'
32k chunk

 From superblock:
mdadm -D /dev/md0 | grep "Chunk Size"

   It's important for testing based on expected environment.

> +mdadm $md0 --grow --chunk=64
> +check reshape
> +check wait

Here too.

> +
> +mdadm -S $md0
> +mdadm -As
> +check state UUU

Also here.

Thanks,
-Zhilong