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Date: Tue, 28 Jul 2009 21:57:30 +0200
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To: Harald Schmalzbauer <h.schmalzbauer@omnilan.de>
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Cc: freebsd-current@freebsd.org, Ivan Voras <ivoras@freebsd.org>
Subject: Re: gmirror provider name limit [Was: Re: geom_label: gpt/labelname
 for gmirror provider?]
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On 2009-07-28 21:34, Harald Schmalzbauer wrote:
>> As far as I can see, this limit applies to gconcat, gjournal, gmirror,
>> graid3, gshsec and gstripe:
>>
>> sys/geom/concat/g_concat.h:96:	char		md_provider[16]; /* Hardcoded provider. */
>> sys/geom/journal/g_journal.h:292:	char		md_provider[16]; /* Hardcoded provider. */
>> sys/geom/mirror/g_mirror.h:250:	char		md_provider[16]; /* Hardcoded provider. */
>> sys/geom/raid3/g_raid3.h:281:	char		md_provider[16]; /* Hardcoded provider. */
>> sys/geom/shsec/g_shsec.h:88:	char		md_provider[16]; /* Hardcoded provider. */
>> sys/geom/stripe/g_stripe.h:91:	char		md_provider[16]; /* Hardcoded provider. */
> 
> Are there any problems to expect when extending the array size?
> To make use og gptid it had to be 43.

It looks like most of the schemes use the md_provider field, with a
hardcoded size of 16 bytes, in their metadata (usually the last sector
on the provider).  So it is impossible to increase, without modifying
the metadata format.