On Fri, Apr 15, 2016 at 6:16 PM, Bryan Smith b.j.smith@ieee.org wrote:
Ross Smith wrote:
I don't think it will be an issue. I've already been bitten by this with a ~1300 efi booted desktops and would welcome the updated configuration.
Speaking of which ...
Q: Shouldn't we be using 260MiB FAT32 as a minimum EFI System Partition (ESP) size going forward, especially as 4KiB logical blocks become regular?
Well, mkdosfs defaults to FAT16 and 4K cluster size on a 200M partition, so that should continue to work, even though the UEFI spec says to use FAT32 on system partitions. So chances are doing nothing isn't going to break anything.
In practice, both Windows and OS X use FAT32, but they also use cluster sizes smaller than 4K. Presumably both of them will transition to 256+M EFI system partitions, rather than use FAT16.
o Just some history (detail) ...
- For NT6.0 (Vista), Microsoft recommended (and its installers
created) a 200MiB FAT32 ESP
- This size has seemingly "stuck" with most distros, even though ...
- For NT6.1+ (7+/2008+), Microsoft recommended (and its installers
created) a 100MiB FAT32 ESP However ...
- If the logical block size is 4KiB, the smallest FAT32 file system is 260MiB
Although ...
- The ESP can be FAT16 (just like good'ole ARC) instead of FAT32
- Every ESP I've used, including Windows 7 and 8 x64, seems to install
fine on a FAT32 ESP
Hence why I'm bringing it up. Just curious if there has been much discussion on this. I did some google searches on the archives and couldn't find anything.
https://bugzilla.redhat.com/show_bug.cgi?id=1046577 https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/ https://www.freedesktop.org/wiki/MatthewGarrett/BootLoaderSpec/ and maybe https://www.redhat.com/archives/anaconda-devel-list/2014-July/msg00002.html
Ideally there'd be an -E flag for mkdosfs to deal with this. The UEFI spec says firmware is expected to support FAT32, FAT16, and FAT12 so it probably doesn't matter that the spec also says the system partition (non-removable) should be FAT32, where only removables get FAT16 or FAT12. The other thing -E would make possible is ensuring the proper invariant "EFI file system" is what's actually being created, rather than pure FAT.