I’ve recently added a second disk to my server, created a single partition /dev/sdb1 and put a ReiserFS filesystem on it. After system reboot I was presented with the grub rescue shell.
Grub Rescue Shell
That was a bit unexpected, as no GRUB2 related changes were made on the /dev/sda disk that day.
GRUB loading.
Welcome to GRUB!
error: unknown filesystem
Entering rescue mode...
If you get a rescue shell, this usually means that GRUB2 failed to load the “normal” module. Live CDs are good, but a rescue shell is sometimes all we need. Sometimes.
Let’s see what disks and partitions are accessible:
grub rescue> ls (hd0)(hd0,msdos1)(hd1)(hd1,msdos4)(hd1,msdos3)(hd1,msdos2)(hd1,msdos1)
Since I have just one partition created on the new disk, it must be (hd0,msdos1).
In this case hd1 should be my primary disk. Having figured out that, the rest becomes more of less straightforward. My /boot partition is on (hd1,1), and / is on (hd1,2). Other partitions include /var and swap.
Let’s check if kernel and initrd images are visible:
grub rescue> ls (hd1,1)/ ./ ../ lost+found/ System.map-3.2.0-4-686-pae config-3.2.0-4-686-pae grub/ vmlinuz-3.2.0-4-686-pae initrd.img-3.2.0-4-686-pae
Set prefix and root to the correct values and load linux module:
grub rescue> set prefix=(hd1,1)/grub grub rescue> set root=(hd1,2) grub rescue> insmod (hd1,1)/grub/linux.mod grub rescue> normal
Once booted into the OS, I mounted my /boot partition and re-installed GRUB2:
# grub-install /dev/sda # update-grub
However, after system reboot I was returned to the same rescue grub shell with “unknown filesystem”.
BIOS
It turned out to be a BIOS boot order setting, which was set to boot from the second disk. Having changed the boot order in BIOS, the problem disappeared.
Note to myself: drive ordering in an operating system may not be the same as the boot drive ordering used by a firmware.
I have fedora and Windows 7 what to do ib grub rescue it is showing :-
And I followed the same steps given by you but I doesnt works.it shows:-
What is installed on hd0 and hd1? Are disks formatted GPT or MSDOS? What is the output of “ls”?
Hey guys I have a little problems.
First of all sorry for my bad english. And it’s first one. :D
Lets begin. I had two OS on my laptop /Lenovo G580/ Ubuntu 14.04 and Kali Linux 1.0.8.
I formatted all sectors were located Ubuntu /in NTFS/.
My grub was on Ubuntu.
So…when i reboot laptop i saw the next sentence:
I tried to change grub direction to Kali linux file, but it does not work.
Help me.
If you had grub installed on Ubuntu and formatted it, then you may need to re-install grub.
not any hd partition works visible….every partition shows “UNKNOWN FILESYSTEM” please tell me what to do now
What happens when you try to use the grub rescue mode? Are you able to see your disks and partitions? Can you post the output of ls?
hey tom I am also facing same problem .i have installed Ubuntu and windows 8.1….all things were working well last night but today I got this error …have done nothing ;(
out put is:
when I presspower button
error:unknown filesystem
Entering rescue mode…
grub rescue > _(and when I type ls)
(hd0) (hd0,msdos5) (hd0, msdos3) (hdo,msdos2) (hdo, msdos1)
and grub rescue > ls (hd0)/
error: unknown filesystem.
same error with other commands (I installed Ubuntu on same hard drive by formatting a drive partition to Ubuntu related filesystem means not ntfs etc) so help plz what to do now
What happens when you run the following:
For ls (hd0,1)/ also facing same problem by getting unknown filesystem.
Boa noite,
erro: unknown fillesystem.
Entering rescue mode…
grub rescue> ls
(hd0) (hd0,msdos6) (hd0,msdos5) (hd0,msdos3) (hd0,msdos2) hd0,msdos1)
grub rescue> set
prefix=(hd0,msdos1)/grub2
root=hd0,msdos1
grub rescue
error: unknown filesystem.
entering rescue mode……….
Nexr
salut;
error: unknown filesystem debian
grub rescue> set prefix=(hd0,msdos8)/grub
grub rescue> set root=(hd0,msdos5)
grub rescue> insmod (hd0,msdos8)/grub/linux.mod
error:file not found
comment faire
Can you post the output of:
Ubuntu 14.04
error: unknown filesystem
Entering rescue mode…
Grub rescue>
When i do
grub rescue> ls
Grub rescue> (hd0) (hd0,msdos1)
grub rescue> ls (hd1,1)/
grub rescue> hd1 cannot get C/H/S values.
Please help me with this.
What’s the output of ls (hd0,1)/ ?
When i write ls (hd1,1)/ , it answer that hd1 cannot get c/h/s values
GRUB loading.
WELCOME to GRUB!
error: unknown filesystem.
Entering rescue mode….
grub rescue>ls
grub rescue>(hd0) (hd0,msdos5) (hd0,msdos2) (hd0,msdos1) (hd1) (hd1,msdos1)
I tried root,prefix command for all partition (hd0,msdos5) (hd0,msdos2) (hd0,msdos1) (hd1,msdos1)
I still get
error:unknown filesystem
Pls provide me solution ..
THANKS
What does ls of every partition show?
i have the same problem:
have a grub rescue> prompt.. ls
(hd0) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1)
when i do ls for each, i get “error: unknown filesystem”
i am running a single boot ubuntu 14.04LTS on a macbook pro.
thanks for any help that you can provide
You’re using GPT, so try the following:
I have same Problem. Unknown filesystem Entering rescue mode.. ls (hd0) (hd0,msdos5) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1) (hd1) please help me
What does ls of each partition show?
It shows Filesystem is unknown for each LS.
What OS do you have installed? If more than one, how are partitions used (separate /boot perhaps)?
Hello
I had 2 os.. Windows 7and boss linux. I had removed boss now i cannot on my laptop.it aksing me the grub rescue command..whatever i give i shows me the unknown filesystem pls help me..my ls
(hd0)(hd0,msdos6)(hd0,msdos5)(hd0,msdos2)(hd0,msdos1)
If you removed Linux, you simply need to fix boot MBR in Windows 7. Check this article.
I have tried for all hard disk but the same problem ocuurs
You may need to reinstall and restore data from a backup.
i give ls (hd0,msdos1)
unknown file system i check all that all could be unknown file system
what can i do plzz help
Not enough information.
Hello. How to solve= error no such partition problem pls?
ls
(Hd0)(hd0,msdos5)(hd0,msdos3)(hd0,msdos2)(hd0,msdos1)
What does ls of each partition show?
Set is cmdpath=(hd0)
Prefix=(hd0,msdos6)/boot/grub
Root=hd0,msdos6
Pls help me to solve the peoblm. Even i could not reinstall another software.
Do you even have that partition on your system? Your previous message has no mention of (hd0,msdos6).
grub rescue> all partion unknow filesystem
ls (hd0,msdos6) (hd0,msdos5) (hd0,msdos3) (hd0, msdos2) (hd0, msdos1)
all f partion unknown file system..
what can i do..
I have to clear CMOS and boot order was changed. Now Its fixed. Thanks!!
You’re welcome!