Re: [PATCH] md: register new md sysfs file 'uuid' read-only

[Phil Turmel <philip@turmel.org>]

On 10/08/2012 12:32 PM, Sebastian Riemer wrote:> Hi Neil,
>
> I must have overseen your answer. We want to use as less mdadm as
> possible - especially for simple checking stuff. The kernel knows best.
> "mdadm -D" reads the data from disk. This means additional disk access.
> It is also possible that this command triggers superblock updates.
> Simple checking stuff shouldn't have to use disk access.
>
> We are planning to use MD RAID a little bit different with e.g. 100 MD
> arrays. Searching for a particular UUID in this bunch of MD devices can
> be difficult without this patch. This is how the kernel represents
> UUIDs. Conversion can be done in user space.
>
> If you like it better in the xxxxxxxx:xxxxxxxx:xxxxxxxx:xxxxxxxx format,
> I can resend the patch in that format.

If you are aiming for consistency, the dm driver(s) have already
established a no-punctuation format for the UUID itself (punctuation
separates UUID type from the UUID) within sysfs.

Regards,

Phil