[Libguestfs] [PATCH] New API: mdadm-stop for stopping MD devices.

[Matthew Booth]

On 23/11/11 16:22, Richard W.M. Jones wrote:
> On Wed, Nov 23, 2011 at 03:02:19PM +0000, Matthew Booth wrote:
>> On 23/11/11 14:43, Wanlong Gao wrote:
>>> This API is used to stop a md device.
>>> When we want to move a device to another md array, we should
>>> stop the md device which contained this device first.
>>
>> I'm not convinced we should extend the md api in libguestfs to
>> active manipulation. I wasn't convinced that mdadm-create was
>> worthwhile either, but it made a test case ever so slightly tidier.
>> To me, MD devices are the domain of physical machines. We need to be
>> able to *read* them (for P2V apart from anything else), but I think
>> manipulation is opening an unnecessary can of worms.
>
> But is there any penalty to carrying this?

I can think of 2:

1. Maintenance: I know you think this is free, but some day mdadm --stop 
might change behaviour, and then the api will break.

2. A false sense of expectation: Having an incomplete md api can only 
lead to frustration. Implementing a complete md api would require a 
large amount of effort for something which we don't have a convincing 
use case for (i.e. nobody's ever going to use it anyway).

Matt
-- 
Matthew Booth, RHCA, RHCSS
Red Hat Engineering, Virtualisation Team

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