Re: [PATCH] btrfs-progs: device: print num_stripes in usage command

[Sidong Yang <realwakka@gmail.com>]

On Mon, Jun 07, 2021 at 09:20:49PM +0200, David Sterba wrote:
> On Sun, May 30, 2021 at 12:56:36PM +0000, Sidong Yang wrote:
> > This patch appends num_stripes for each chunks in device usage commands.
> > It helps to see profiles easily. The output is like below.
> > 
> > /dev/vdb, ID: 1
> >    Device size:             1.00GiB
> >    Device slack:              0.00B
> >    Data,single[1]:        120.00MiB
> >    Metadata,DUP[2]:       102.38MiB
> >    System,DUP[2]:          16.00MiB
> >    Unallocated:           785.62MiB
> 
Hi David. Thanks for review!

> This is example of single and dup, but the whole point was to print that
> for the striped profiles, like is shown in the issue
> https://github.com/kdave/btrfs-progs/issues/372 , so it needs to be
> conditional.

Okay, striped profiles need to be printed. I read some page from
wikipedia about raid. and I got that RAID 0,5,6,10 supports striping.
Those need to be printed and no printing for RAID 1, single, dup.

> 
> As the mirrored profiles have a fixed number of copies, there's no doubt
> on how many devices are printed, same for single and dup.
> 
> I'm more inclined to use the "/" as separator: 'RAID6/3' it's more like
> "raid6 on three devices", the "[]" looks like indexing. "," is used as
> separator of the type so it won't be as simple to parse that.

I agree. I'll use "/" for next version.