tekka
Enthusiast
Enthusiast

rhel6 inaccessible when forcedly put to single user mode

hello,

I 'm experimenting a problem in ESXi4 version 4.1 (build 433742) and RH EL 6 guests.

I installed VMware tools and it detected some kernel modules already present so it didn't overwrite them.

Updated the system and all is ok during normal operations.

But if I simulate a file system problem at boot, I notice I can not log in anymore and have to go through a cd iso to access the system and correct it....

- mkdir /test
- add an entry in fstab so that it refers to a not existent disk/partition to be mounted under /test; eg without having sdb inside the guest:
/dev/sdb1               /test       ext4    defaults        1 2
- reboot of the server

Due to the problem of missing filesystem it puts you in a single user environment where you have to give the root password before proceeding.

But as soon as you press the second character of the password it seems to intercept a new line because it replies uncorrect password and so on....

And you are unable to proceed. Ctrl-D or Shift+PgUp to scroll terminal work. Also send ctrl+Alt+Del from vi client works...

I have attached an image

Tested on rh el 6.1 with kernels 2.6.32-131.0.15.el6.x86_64 and 2.6.32-71.18.2.el6.x86_64.

Tested on CentOS +CR repo and kernel 2.6.32-131.12.1.el6.x86_64

I have no way right now to test in other physical/virtual environments to check if this is a problem of rh el 6 itself or only in interaction with VMware console.

Anyone that can verify?

Thanks in advance,

Gianluca

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tekka
Enthusiast
Enthusiast

Just to say that it was a bug present in RH EL 6.0 and 6.1 + updates.

Workaround was to put

rd_NO_PLYMOUTH

parameter in grub.conf kernel line

This is now solved at least in 6.2 install media.

the problem arose at least in Qemu/KVM and Vmware virtual guests.

Probably a few guys put in forced single user mode with Linux... based on no answers until now 😉

BTW: related bug should be this one

https://bugzilla.redhat.com/show_bug.cgi?id=741515

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