(and welcome to a new "let's hate on Microsoft" thread)
Asus laptop with a 500GB SSD drive, with a 150GB NTFS Windows partition and a 350GB Ubuntu 20.04 partition (almost sure it is ext4). Dual boot with GRUB/Ubuntu having priority over Windows. Important data on the Ubuntu partition, not on the Windows one.
After a 1-hour Windows update, without any incident (no power outage or anything), the computer boots into the GRUB command line ("grub>", not "grub rescue>"). More annoyingly, this also happens when a live USB key is plugged (18.04, tested fine on another laptop). When using "exit" on the prompt Windows boots properly.
That was the overview, now for the specifics. With the live USB key first a screen quickly appears that reads
Failed to open EFI\BOOT\grubx64.efi - Not Found
Failed to load image EFI\BOOT\grubx64.efi - Not Found
start_image() returned Not Found
then after a second the "grub>" prompt appears
On the "grub>" prompt, ls returns
(proc) (hd0) (hd0,msdos1) (hd1) (hd2) (hd2,gpt6) (hd2,gpt5) (hd2,gpt4) (hd2,gpt3) (hd2,gpt2) (hd2,gpt1)
ls (proc) returns
Device proc: Filesystem type procfs - Sector size 512B - Total size 0KiB
The live USB is hd0, and as expected ls (hd0,1) returns
Partition hd0,msdos1: Filesystem type fat - Label 'Ubuntu 18_0', UUID 864E-2850 - Partition start at 1024KiB - Total size 15150080KiB
I do not know what hd1 is ; the computer previously had a HDD that was replaced with the SSD a few years back, perhaps it's a trace of that. ls (hd1) returns
Device hd1: No known filesystem detected - Sector size 2048B - Total size 514KiB
hd2 is the real hard drive. ls (hd2) describes the device
Device hd2: No known filesystem detected - Sector size 512B - Total size 488386584KiB
ls (hd2,xx) for xx= 6 to 1 describes the partitions
Partition hd2,6: No known filesystem detected - Partition start at 14684736KiB - Total size 341580800KiB
Partition hd2,5: Filesystem type ntfs, UUID84127C1A127C1380 - Partition start at 146205696KiB - Total size 598016KiB
Partition hd2,4: Filesystem type ntfs, UUID22FE5C86FE5C53DF - Partition start at 661504KiB - Total size 145543516KiB
Partition hd2,3: No known filesystem detected - Partition start at 645120KiB - Total size 16384KiB
Partition hd2,2: Filesystem type fat, UUID 0057-5017 - Partition start at 542720KiB - Total size 102400KiB
Partition hd2,1: Filesystem type ntfs, Label 'Rcupration' - Partition start at 1024KiB - Total size 541696KiB
hd2,6 seems to be the 350GB Ubuntu partition. As far as I can tell it should not say "No known filesystem detected", in another laptop the ext structure is detected correctly by the grub ls command.
hd2,4 seems to be the Windows partition.
hd2,1 has a weird name because accents in French don't display
When I try to boot from the linux partition using
set prefix=(hd2,gpt6)/boot/grub
set root=(hd2,gpt6)
insmod normal
normal
nothing happens (I suppose it is expected if it can't tell the filesystem). When I try booting the key, using
set prefix=(hd0,1)/boot/grub
set root=(hd0,1)
insmod normal
normal
I get the live USB prompt, but then when I go for "Try Ubuntu without installing", or any other option, I get
error: /casper/vmlinuz has invalid signature.
error: you need to load the kernel first.
Press any key to continue...
then back to the live key menu, stuck in a loop. This is slightly weird, because earlier it warned me that grubx64.efi was not found, and from what I gather (Update Windows 8 broke my GRUB) the fact that it did not ask for shimx64.efi means that Secure Boot is disabled, but then what is this signature thing ? In any case, the lack of a proper boot on the live USB key prevents me from using common repair tools.
Now I can still type "exit" and then Windows boots normally. On Windows, I tried downloading Testdisk. Testdisk does detect the Linux partition properly, as follows :
Partition Start End Size in sectors
1 P Windows Recovery Env 2048 1085439 1083392 [Basic data partition]
2 P EFI System 1085440 1290239 204800 [EFI system partition]
No FAT, NTFS, ext2, JFS, Reiser, cramfs or XFS marker
3 P MS Reserved 1290240 1323007 32768 [Microsoft reserved partition]
3 P MS Reserved 1290240 1323007 32768 [Microsoft reserved partition]
4 P MS Data 1323008 292410039 291087032 [Basic data partition]
5 P Windows Recovery Env 292411392 293607423 1196032
6 P Linux filesys. data 293609472 976771071 683161600
However when I go into that partition (with Advanced Utils) and try to list the files, I get
Support for this filesystem wasn't enabled during compilation
Only Windows boots properly, so I do not have another version on hand to try to work on the ext4 partition. Also I just downloaded the .exe and did not compile it myself, as I am not experienced enough to do that.
Some threads over at the Testdisk forums hint that when a partition is listed twice as 3 above it means there is a problem.
So...
My main goal is to gain access to the files of the Ubuntu partition, although repairing everything as it was yesterday would be really nice. I see a few possible avenues :
- somehow make GRUB boot the Ubuntu partition, reading it as the ext4 it is
- make GRUB boot the live USB key properly (with that signature thing), then use recovery tools from there
- use Testdisk (on Windows) to repair the ext4 partition so that GRUB can see it properly, or another similar tool in Windows
- use any tool to read the Ubuntu partition as ext4, get the files out, and throw the computer out the window.
Does anyone have an idea ?
Either way, thanks for reading !
