Talk:GUID Partition Table

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[edit] New version created by Scorpiuss

I've created a new version of the GPT page. The fundamentals are all there. Could use a chart of the things represented at each bit position. Microsoft's got a nice one on the external link indicated (which, by the way, is a great source).

-Scorpiuss, Aug 26 2005, 13:25 GMT

[edit] GUID Partition IDs

I just put a little collection of GUID partition type IDs in my talk page, but it lacks the UFS ones of FreeBSD and the HFS ones (OS X includes a the BSD's gpt partition tool, and creates HFS partitions by default, who knows why, as OS X uses Apple Partition Map and not GPT).

—Claunia 00:42, 27 August 2005 (UTC)

Put it yesterday in the article —Claunia 19:58, 27 August 2005 (UTC)
The future Intel-based Macs use GPT. Bo Lindbergh 18:34, 4 November 2005 (UTC)
Do you have any kind of confirmation? Please, post reference. —Claunia 11:13, 5 November 2005 (UTC)
Just a high-confidence guess.
  • Universal Binary Programming Guidelines (PDF) says "The partition format of the disk on a Macintosh using an Intel microprocessor differs from that using a PowerPC microprocessor."
  • The developer tools for Mac OS X 10.4 includes the header file /System/Library/Frameworks/IOKit.framework/Versions/A/Headers/storage/IOGUIDPartitionScheme.h which wasn't there in 10.3.
Bo Lindbergh 15:04, 9 November 2005 (UTC)
Yes but that is only a speculation.
Windows 2003 and XP can both use GPT under x86 and x86-64, but they don't boot from it.
MacOS X 10.4 recognizes, formats (command-line), and can use GPT disks, but don't boot from it.
There are also rumours that Apple is questioning between using BIOS or EFI in their new machines.
—Claunia 16:27, 9 November 2005 (UTC)

[edit] EFI System partition GUID contradiction

The GUID for an EFISys partition under the Partition Entries section is different than the one in the list of GUIDs. On the MS page linked at the bottom, the one given in the Partition Entries section is given.

-Scorpiuss

[edit] GPT Windows only?

I'm reading this article, very interesting and all, but then I read, 'only 64bit Windows' and later '64 bit Windows 2003 Server'. I'm sure other operating systems will use GPT disks, like linux, as they have GUID entries? Shouldn't this be changed to '64bit OS'?

[edit] Questions

With that in mind, what is the status of GPT? I'd expect more info about this here, is it a standard allready? Do operation systems support it? Windows? Linux? (Will older OS's support it? will it only work on 64 bit and not 32 bit and why?) Could I convert and start using GPT now on my old linux pc?

Also, what happend to primary/logical partitions. Is it safe to assume we simply have up to 128 partitions. No more worring about primaries, secondaries and bootables?

GPT is part of the EFI specification, which seems to have been accepted as an
industry standard.
The leagacy PC BIOS doesn't have the ability to boot off of a GPT partitioned disk.
However, you could use GPT to partition disks that are not booted from, as Linux
(with GPT enabled, on any platform) and some newer (most, if not all 64-bit)
Microsoft OSes understand GPT. However, the GPT method of partitioning is not
as widely supported as MBR.
GPT is a new, improved way to divide disks into partitions; redesigned almost from
scratch. GPT does not need to diferentiate between the ways a partition could be
defined, as with GPT there is only one way.
128 partitions is just a Microsoft default, it seems the minimum would be 0 (although
that's not really useful), and the maximum limited only by the 32-bit number used to
define how many entries are in the partition table and the space needed to store the
table.
Jakllsch 04:18, 5 May 2006 (UTC)
As far as booting from GPT goes, you DO NOT need EFI to do it. HP already has an implementation that can boot GPT volumes from good old BIOS.[1] 142.150.48.191 (talk) 21:01, 10 March 2008 (UTC)

[edit] "the same GUID for their respective data partitions"

What's with the comment Note: Linux and Windows use the same GUID for their respective data partitions? From the table, the GUIDs look quite different... --moof 02:51, 29 July 2006 (UTC)

Look closer.
--Jakllsch 21:51, 1 August 2006 (UTC)
There is something fundamentally wrong with the idea of two different systems using the same "Globally Unique" ID, since it is no longer unique then. I think this article should mention something about how this could happen, and who allocates these not-so-globally-unique IDs. Zuiram 17:54, 13 October 2006 (UTC)

[edit] OS and utility support ?

Which operating systems support GPT ? What tools exist that can work with GPT (like partitioners, backup utils, etc...; I know parted supports it, at least they claim so)

--Xerces8 (talk) 12:00, 17 November 2007 (UTC)

[edit] ZFS GUID

ZFS on Mac OS X uses the same GUID as the /usr partition on Solaris. I couldn't find any external sources for it, but the following command will reveal the descriptors for ZFS when executed on a Mac running Mac OS X 10.5. I have the ZFS developer preview installed, but that shouldn't matter.

% grep -A1 FSFormatContentMask /System/Library/Filesystems/zfs.fs/Contents/Info.plist
                        <key>FSFormatContentMask</key>
                        <string>6A898CC3-1DD2-11B2-99A6-080020736631</string>

--DanChr (talk) 04:30, 19 November 2007 (UTC)