GPT partition type (GUID) for (g)journal provider partition

[John Baldwin]

On Thursday, September 23, 2010 2:44:24 am Carl wrote:
> On 2010-09-22 3:32 AM, Carl wrote:
> > I am using GPT for disk layout and I wish to use a dedicated partition
> > for a gjournal journal provider rather than combining the data and
> > journal into the same provider/partition. The question is this: What
> > partition type (GUID) do I use for the journal partition?
> >
> > The gpart(8) man page lists a number of symbolic names for different
> > FreeBSD partition types, but none seem appropriate for the task.
> >
> > For those that wonder, my reason for separating data and journal is that
> > I am hoping to make up a little bit of the tremendous performance hit
> > that gjournal causes by locating a journal provider in the fastest
> > region of the disk even though its corresponding data provider must
> > necessarily be located in the slower region of the disk. Is there a flaw
> > in that thinking?
> 
> Anyone know the GUID I need to use?
> 
> Since posting the question I've been trying in vain to find a document 
> listing all known GPT partition type GUIDs. Apple claims it's in the 
> UEFI specification, but it isn't. The largest list is in this Wikipedia 
> article:
> 
>    http://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs
> 
> which provides no references as to where most of the list contents come 
> from.
> 
> How and by who did the FreeBSD GUIDs get defined? Are there more than 
> appear in that Wikipedia article? Is there no governing body/publication 
> for this sort of thing?

The GUID's for FreeBSD were generated by FreeBSD developers.  GUID creation is 
not explicitly coordinated with UEFI.  Instead, GUID's are designed to have a 
very low probability of collisions.  You can ask pjd@ if he thinks gjournal 
warrants a separate partition type and if so a new GUID can be generated and 
added to <sys/gpt.h>

-- 
John Baldwin