Messages in this thread | | | Subject | Re: [PATCH v2] md/raid0: add config parameters to specify zone layout | From | Jason Baron <> | Date | Mon, 27 Apr 2020 16:59:54 -0400 |
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On 4/24/20 7:22 PM, Song Liu wrote: > > >> On Mar 30, 2020, at 9:00 AM, Jason Baron <jbaron@akamai.com> wrote: >> >> Let's add some CONFIG_* options to directly configure the raid0 layout >> if you know in advance how your raid0 array was created. This can be >> simpler than having to manage module or kernel command-line parameters. >> >> If the raid0 array was created by a pre-3.14 kernel, use >> RAID0_ORIG_LAYOUT. If the raid0 array was created by a 3.14 or newer >> kernel then select RAID0_ALT_MULTIZONE_LAYOUT. Otherwise, the default >> setting is RAID0_LAYOUT_NONE, in which case the current behavior of >> needing to specify a module parameter raid0.default_layout=1|2 is >> preserved. >> >> Cc: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> >> Cc: NeilBrown <neilb@suse.de> >> Cc: Song Liu <songliubraving@fb.com> >> Signed-off-by: Jason Baron <jbaron@akamai.com> > > This patch looks good. However, I am not sure whether the user will > recompile the kernel for a different default value. Do you have real > world use case for this? > > Thanks, > Song >
Hi Song,
Yes, we knew that all our raid0 arrays were created with >=3.14 kernels, and thus we wanted a way to specify the new layout without needing to add to the command line or a module parameter. For us, maintaining a CONFIG_* option is just simpler.
Thanks,
-Jason
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