On Thu, Aug 25, 2011 at 2:19 AM, Gour-Gadadhara Dasa email@example.com wrote:
On Wed, 24 Aug 2011 12:44:10 -0500 C Anthony Risinger firstname.lastname@example.org wrote:
unfortunately you can only do /boot on btrfs if you use a single disk due to bootloader limitations:
Is it only bootloader limitation considering that wiki page says: "This setup does not support btrfs RAID because a separate boot partition/device is needed, ie. only one drive allowed. Pending releases of mkinitcpio-btrfs will attempt to provide solutions." ?
im not sure im understanding correctly ... mkinitcpio-btrfs is just an initcpio hook performing a handful of trixy things to "rollback in time", ie. boot an older snapshot. everything it does is orthogonal to the /boot problem ... though i had some experimentations using a two-stage system that booted a minimal kernel far enough to load the real kernel off the btrfs array -- along with other activity this could "enable" /boot on a btrfs array -- not even tested yet though.
fundamentally syslinux and friends (AFAIK) are not capable of reading a disk if part of an array. syslinux can't even look inside a subvolume ... hence kernel rollbacks are not straightforward.
you *can* however have / on btrfs, *and* an array ... so long as your /boot is still using `md` + <other FS>. maybe btrfs could even be that FS ... not sure. for this to work you just need the `btrfs` hook included with Arch, or you need to pass all the devices in the array as a mount option (eg. via `rootflags` on kernel bootline)