Thankyou for the further clarification.
My apologies for not being clear about my end goal. Indeed, I do wish to do remapping because I am coding a ZAC simulator.
________________________________________
From: Mike Snitzer [snitzer@xxxxxxxxxx]
Sent: Friday, July 11, 2014 5:36 PM
To: John Utz
Cc: dm-devel@xxxxxxxxxx
Subject: Re: device mapper target vs personality, how do you decide to pick one or the other?
On Fri, Jul 11 2014 at 5:56pm -0400,
John Utz <John.Utz@xxxxxxx> wrote:
> Hi Mike
>
> tnx so much for the prompt response!
>
> sorry i wasnt clear enuf, example of the 'personality code' that i was
> writing about below.
...
> FOR EXAMPLE, here is a little bit of linear.c that contains it:
>
> static struct md_personality linear_personality =
> {
> .name = "linear",
> .level = LEVEL_LINEAR,
> .owner = THIS_MODULE,
> .make_request = linear_make_request,
> .run = linear_run,
> .stop = linear_stop,
> .status = linear_status,
> .hot_add_disk = linear_add,
> .size = linear_size,
> };
>
> static int __init linear_init (void)
> {
> return register_md_personality (&linear_personality);
> }
>
> static void linear_exit (void)
> {
> unregister_md_personality (&linear_personality);
> }
The above is MD raid code. So what you're talking about are the
different MD raid personalities.
> > so, based on this speculation, i *think* i should be using the target
> > construct for the new device mapper module that i am currently
> > coding.
> >
> > am i correct?
>
> Probably.
The target construct is provided by DM. You haven;t said what you're
looking to do but if it is remapping IO and has nothing to do with raid
then you'd probably want to develop a new DM target.
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
