On Sat, Aug 20, 2016 at 1:38 PM, Alberto Bursi <alberto.bu...@outlook.it> wrote: > > > On 08/20/2016 05:21 PM, Chris Murphy wrote: >> >> On Fri, Aug 19, 2016 at 10:00 PM, Bearcat Şándor >> <bearcatsan...@gmail.com> wrote: >>> >>> I have a btrfs non-raid file system that i'd like to convert to >>> raid10. This single device has my efi boot partion on it, so it's >>> partitioned into sda1 and sda2. I have 3 other discs (sdc-sde) that >>> i'd like to make partition-less systems and then add them to the first >>> disc (sda) using the steps in the conversion section of the wiki >>> >>> (https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices#Conversion). >>> >>> My concern in that i'll be mixing a partitioned and partition-less >>> system. Will that work or will i hose myself? >> >> That will work, but you'll likely be in a hosed situation later should >> you ever lose a drive so I don't recommend this layout. >> >> a. You have the ESP on only one drive, so it's still a single point of >> failure. If that drive dies you can't boot. There are various ways >> around that but they all pretty much suck right now from an end user >> perspective. Basically redundant boot on UEFI with Linux right now is >> pretty much shit. You have to be a bootloader expert to set it up, >> maintain it with software updates, and fix it should things go bad. > > The usual solution to this is keeping the ESP on a separate (small) flash > drive.
It's a good idea. It'd be nice if installers offered to put the ESP on non-boot USB (so it's not overwriting the installer media). > I still vehemently hate the fact that they couldn't provide like 2 MB of > space on an onboard NOR flash chip to store a bootloader. Seriously, rEFInd > with filesystem drivers to boot off btrfs and ext and whatever needs like > 1.5 MB. Needs to be bigger. The secure boot stuff takes up more room than this, about 6-8MiB depending on the distro. And then more room needed for dual booting let alone triple, which of course no manufacturer really cares about. > But no, they need to make a stupid system that is hardcoded to a disk, and > to a crappy filesystem. Ahh well the onboard flash could just appear as a small SATA or sdcard or USB mass storage devices, whatever's easiest to implement. FAT leaves a lot to be desired but it's pretty universally supported and almost trivial to repair *if* the volume is repairable in the first place. The much bigger issue with ESP on Linux is this neurotic tendency of distros to persistently mount shit that does not need to be mounted. Like the ESP, and even the dedicated boot volume. They only need to be mounted when being updated and then should be umounted. And worse the convention is to do nested mount with /boot and then /boot/efi for the ESP so it's twice as bad a practice. By virtue of mounting the ESP the dirty bit is set, so any crash means it must be fsck'd and if that doesn't work, it's game over for that volume. Fragile setup. -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
