Warren Block wrote:
> On Wed, 14 Nov 2012, Ronald F. Guilmette wrote:
>> I'm looking at the examples section of the gpart(8) man page. May I
>> assume that if I just want to merely ``try out'' GPT... you know...
>> taking it out on the road for a first time test run... that I can
>> just do the first five (5) commands listed under EXAMPLES and then
>> that will be enough to go ahead and try installing FreeBSD into the
>> created freebsd-ufs partition?
>> Even assuming that the answer is yes, I have still more questions...
>> Where are these magic numbers coming from?? I am specifically talking
>> about the number "34" in the "-b 34" option and also the number "162"
>> in the "-b 162" option. Tha man page just tosses those into the example
>> command lines without saying a word about them. And you can probably
>> guess what it is that is especially troubling to me about them... neither
>> one of them is divisible by 8 (i.e. 4KB/512B). So would the examples
>> in the current gpart(8) man page produce an Epic Fail when and if they
>> were used with a modern "Advanced Format" drive?
> -b is the beginning block of a partition. 34 is a magic value, the size
> of a standard GPT partition table. A good overall reference on GPT is
> the Wikipedia page: http://en.wikipedia.org/wiki/GUID_Partition_Table
> Remember that the man page is a reference, not a tutorial. I wanted
> more specific notes that followed best practices, and that was the
> source for this article:
> In general, you create a "partition scheme" first. This can be MBR,
> GPT, or others. (But use GPT.)
> Rather than combine the bootcode with the partition table, GPT just uses
> a small partition for it. Since the standard GPT allows for up to 128
> partitions, there's no reason not to use them.
> Next come other partitions for UFS or ZFS filesystems or swap.
> That's it, really. The rest is details the man page can explain, like
> additional options for alignment. (The creation of the first UFS
> partition in the article does not use -a because older versions of gpart
> did unexpected things when -a and -b were combined. The alignment
> produced is correct.)
> freebsd-questi...@freebsd.org mailing list
> To unsubscribe, send any mail to