gmirror provider name limit [Was: Re: geom_label: gpt/labelname for gmirror provider?]

Marius Nünnerich marius at
Tue Jul 28 20:59:58 UTC 2009

On Tue, Jul 28, 2009 at 22:05, Harald
Schmalzbauer<h.schmalzbauer at> wrote:
> Ivan Voras schrieb am 28.07.2009 21:55 (localtime):
> ...
>>>> sys/geom/stripe/g_stripe.h:91:  char            md_provider[16]; /*
>>>> Hardcoded provider. */
>>> Are there any problems to expect when extending the array size?
>> If you mean the char array of the provider name then yes, it cannot be
>> done without introducing a new metadata version (and then if it fits).
> Oic, thanks for the hint. I forogt about the metadata... *slap*
>>> To make use og gptid it had to be 43.
>> I don't follow you on this - why gptid and why 43?
> The automatically generated gptid is 36 cahracters plus "gptid/" to use that
> for a provider name. In my case I'd like to assign the following label:
> fbsd8GUNE-root_RAID1prov.1of2
> It's 30 characters, so I thought using the gptid length was a feasible
> limit...

The current size of the gmirror metadata is 135 bytes so a
providername of 64 would easily fit but I'm not sure it's worth the
hassle. Maybe one could include it if/when there is a new version.
Anyway till then it should be documented and there should be an error
message from the utils which create the mirror (and the other setups).

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