Fedora 16 is more than two months away from final, stable release, but pre-Alpha installation ISO images have been floating around. News from the Fedora camp have already indicated that btrfs will be the default file system on Fedora 16, joining the ranks of MeeGo, the first (Linux) distribution to use btrfs as the default file system.

With several articles already published about Fedora and btrfs (see the latest here), I downloaded a pre-Alpha image just to see what the new partitioning scheme will be on Anaconda, the Fedora system installation program, with btrfs. If btrfs is to be the default, a file system with a built-in volume management system, what will happen to LVM?

If you are new to Fedora, LVM, the Linux Logical Volume Manager, is the default disk partitioning scheme, with ext4 as the preferred file system.

The images in this article show what awaits you on Fedora 16, and as I discovered, btrfs is not even in the picture, for now.

The first image shows the usual disk partitioning methods on Anaconda, with a new option in the list of check boxes below them. That new option is “Use LVM.” It is enabled by default.
Partition Methods on Fedora 16 Anaconda

And if “Use LVM” is left enabled, Anaconda creates a set of partitions and logical volumes slightly different from what Fedora users are used to. Notice in the image below that the first partition is not a boot partition, but an unformatted partition with a “BIOS Boot” file system, and only 1 MB in size. What does this mean?
Default LVM Partitions on Fedora 16 Anaconda

Well, “BIOS Boot” is not exactly a file system, in the traditional sense, but a flag passed to an unformatted partition to signal to the installer that a GPT partition table is in use, instead of the traditional MBR partition table.

GPT, the GUID Partition Table, is an alternate disk partition table scheme that solves two problems associated with the MBR (Master boot Record) partition table. It allows the configuration of more than four primary partitions, the maximum supported by MBR, and also supports disk partitions of more than 2 TB.

So GPT will be the default partition table scheme on Fedora 16. That will make it the second Linux distribution reviewed on this website that will use GPT out of the box. Chakra is the first one. See disk partitioning guide for Chakra 2011.4 for an example of how to configure a GPT-based partitioning scheme on Chakra, a Linux distribution derived from Arch Linux.

But what will the partitioning scheme look like if “Use LVM” is disabled? That is revealed in the image below. Notice that there are five partitions, all of them primary. In an MBR partition table, the fourth partition would have been an extended partition, with Swap and /home as logical partitions. Did you also notice that the partitions are not using btrfs, which is supposed to be the default, but the same ext4 that is used on current and earlier versions of Fedora. This is not even the alpha release, which is due on August 16 (2011), so I will not assume anything about the status of btrfs.
Default GPT Partitions on Fedora 16 Anaconda

If you have any doubt that a 1 MB, unformatted partition with “BIOS Boot” file system signals GPT, this dialog prompt should put that to rest.
GPT Partition Fedora 16 Anaconda

Now that we know that GPT will be in use on Fedora 16, what impact will that have when you attempt to dual-boot Fedora 16 and another operating system, like Windows or another Linux distribution? It is still too early to answer that, but in about a weeks time, when fedora 16 Alpha is released, we should know more.