Public bug reported:
A small but increasing number of disks use 4KiB native ("4Kn") sectors
-- that is, they use 4096-byte physical sectors (which is now common)
*AND* 4096-byte LOGICAL sectors (which is uncommon, "translation" to
512-byte sectors being the norm). Today, most 4Kn disks are external USB
drives; however, a few 4Kn internal disks are now available, such as the
8TB HGST 0F23666. Such disks are likely to become more common in the
future.
In testing an HGST 0F23666, I've found that the Ubuntu 16.04 beta2
Ubiquity desktop installer works fine with the disk in UEFI mode on an
ASUS P8H77-I motherboard; however, in BIOS mode Ubiquity happily
installs to the disk, but the install Ubuntu then fails to boot. The
system ran through its POST just fine, but then showed a blinking
underscore cursor in the top-left corner of the screen; there was no
GRUB screen or error message.
In another test using a Dell server computer, a MAAS-mediated BIOS-mode
install seemed to succeed, but failed on reboot with the same symptoms
as on the ASUS machine. The identical symptoms suggest either a BIOS or
GRUB bug.
I don't know if the problem is in the BIOS or in GRUB; however, 512-byte
sector size assumptions have long riddled the software chain, and may
never be fixed in BIOSes and CSMs, so even if there's a GRUB bug,
BIOS/CSM bugs are likely to cause problems on many systems. Therefore,
it seems prudent to display a prominent warning in Ubiquity when it
detects a BIOS-mode install that is underway to a 4Kn disk. I recommend
something along these lines:
"You appear to be installing to a disk with 4096-byte logical sectors in
BIOS mode. This installation may not work. A UEFI-based installation is
more likely to succeed. Continue anyway (Y/N)?"
The lack of such a warning is likely to result in user frustration with
failures if/when 4Kn disks become more common.
** Affects: ubiquity (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1562537
Title:
Ubiquity installs to 4Kn disk in BIOS mode, but installation won't
boot
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1562537/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
