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

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).