[SOLVED] The new 2-partition format vs the older 4-partition format.

Question

Before, the automatic Arch installer would create 4 partitions (boot, swap, root, and home).
That is gone now, and the Beginner's Guide now tells you to create only two partitions (root and home).
Is it safe/secure/crash-proof to have the boot loader in the root partition instead of separately? Am I right to assume that the swap partition was dropped due to memory being abundant nowadays?
Last edited by amadar (2012-12-05 08:55:07)

Answer 1

I'll add that a separate /boot partition has historically risen and fallen in importance. Currently, we're at or near a low point for its importance, but it could be that it's rising again in importance, for a couple of reasons:
On older BIOS-based computers, a 2TiB limit exists in what can be handled by boot loaders under at least some circumstances. With 3TB (~2.7TiB) hard disks now available, creating a separate /boot partition that resides below the 2TiB mark could be important on such disks. Note that I'm unclear about just how common this 2TiB limit is on BIOS boot loaders. Most modern BIOSes are supposed to have much higher limits than that, but my one test under VirtualBox showed that GRUB 2 was unable to boot from a kernel placed above the 2TiB mark. I don't know if that was a VirtualBox problem or a GRUB 2 problem. There's a separate 2TiB limit on the Master Boot Record (MBR) partitioning system, but you can use the GUID Partition Table (GPT) even on bigger disks, so this BIOS boot limitation is independent of the 2TiB MBR limit.
On newer EFI-based computers, some boot loaders (ELILO and the EFI stub loader; but this also means the rEFInd and gummiboot boot managers) require that the kernel be readable by the firmware. Normally this means placing the kernel on the EFI System Partition (ESP), but with the help of existing ext2fs/ext3fs and ReiserFS drivers, the EFI can read kernels from those filesystems. Since most people have moved on to ext4fs, XFS, JFS, or Btrfs for their root (/) filesystems, having /boot on a FAT, ext2fs, ext3fs, or ReiserFS partition gives you added flexibility. Many in the Arch community are simply ensuring that their ESPs are big enough to hold several kernels and mounting them at /boot, which is arguably the simplest way to do it. Having a separate dedicated /boot partition (independent of the ESP) makes sense in some situations, though, such as if you're multi-booting with another Linux distribution. If each one has its own /boot, there's less risk of getting your kernels confused.
Because both over-2TiB disks and EFI are becoming more common, IMHO it's wise to begin re-emphasizing the utility of a separate /boot partition; chances are more people will start wanting or needing it in the near future. There are also some more exotic reasons to want a separate /boot partition, such as if you're using an encrypted root filesystem or GRUB Legacy along with a RAID or LVM setup.