grub-probe fails to recognize valid EXT4 partition

[Nonny Mouse]

I have 2 x 1TB SSD, each with 32G ext4 and about 900G btrfs in RAID1 configuration. The two ext4 partitions hold mirror image installations of Ubuntu Server 20.04, intended as failovers to each other. The only difference is that one has ea_inode and encrypt options while the other does not. On the drive with these options grub-mkconfig fails with unknown file system (in grub-probe) and attempting to re-boot fails, dropping into grub recovery. This happens on both drives, if the options are enabled, but boots normally without them.

Noticed the problem after an update to the kernel which, of course, attempted to update grub.cnf, and also when I attempted to grub-install on the drive with the options.

Knowing of a similar problem in os-probe about two years ago, I suspect grub-probe is not recognizing these options in the file system itself, and therefore not recognizing an ext4 file system.

I actually need these features . . .

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: grub2 (not installed)
ProcVersionSignature: Ubuntu 5.4.0-54.60-generic 5.4.65
Uname: Linux 5.4.0-54-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.13
Architecture: amd64
CasperMD5CheckResult: skip
Date: Wed Dec 2 13:42:40 2020
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.UTF-8
 TERM=xterm-256color
 PATH=(custom, no user)
SourcePackage: grub2
UpgradeStatus: Upgraded to focal on 2020-07-29 (126 days ago)

[Nonny Mouse (nonnymus)]

Note that the ext4 fs with these features mounts and operates normally.