[Bug 1059827] Re: Non trivial grub2 installs no longer fit in small embed areas

[D3m0n1q_733rz]

Sorry, I did get a little confused over the sectors thing.  The 63rd LBA sector is the starting point for the 0MB boundary of partitions usually.  I wasn't thinking straight.  I'm used to using the MB settings for partitioning instead.  Anyhow, the normal Grub2 install for any partition that's not BtrFS can fit into the MBR area with no problem normally.  However, a larger area is required if you're going to use a BtrFS partition since the data on how to read such a partition in Grub2 makes the boot program a bit larger than the MBR size.  Recall that I said Core.img is particularly large.  I'll have to check on my installation to see where I had to start it at later.  But it is a problem that should be addressed or at least warned about in the installation.
As for the installation report, it should mention that Grub2 failed to install properly and should return to the partitioning step to address the issue.  Highlighting the issue may also be beneficial to users.  However, with newer hard drives, they utilize 4K sector sizes to increase capacity.  This should be taken into account in case the 512b emulation ceases.  It's known as Advanced Format and can be a pain in the rear if you're not already familiar with it.  This will make 256 sectors equal to 1 MB instead.
Anyhow, I'll be sure to check on how I've managed to install BtrFS and where my partitions start and end so that I can toss together a sort of guideline for failsafes.

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https://bugs.launchpad.net/bugs/1059827

Title:
  Non trivial grub2 installs no longer fit in small embed areas

Status in “grub2” package in Ubuntu:
  Triaged
Status in “ubiquity” package in Ubuntu:
  New

Bug description:
  Traditionally the first boot track of the disk was left unpartitioned.
  This area is used to embed the grub2 core.img file.  The size of this
  area used to typically be 62 sectors.  In recent years the typical
  size has changed to 2048 sectors to keep the partitions aligned to a 1
  MiB boundary for performance reasons on SSDs and newer hard disks with
  4KiB sector sizes.  All but the most trivial configurations of grub no
  longer fit in the old 62 sector size embed area.  This results in grub
  complaining that your embed area is unusually small.

  Upstream appears to have no desire to support such configurations, so
  this is unlikely to be fixed, but I will leave this bug report open
  for now.  The workaround for the problem is to repartition the disk
  with modern partitioning tools that will align partitions to 1MiB,
  thus leaving 2048 sectors for the embed area.

  Another workaround is to setup a simple ext4 /boot partition rather
  than try to boot directly from raid or lvm or btrfs.

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