Booting stuck at progress bar centos 6.8

[azazur]

HI
i am running centos 6.8 in XEN environment;
the server ram was 3 GB and i did increase ram to 4 GB and reboot but the server did not come back online it got stuck on progress bar (picture attached)... i did go back to 3 GB RAM and try to start but same happen

can anyone help me, how can i fix that error?

[TrevorH]

Either press Esc to get rid of the bar so you can see the underlying messages or, probably better as that might not show things that have already been issued, reboot and at the grub menu, edit the current entry by pressing 'e' then edit the kernel entry and scroll along the parameters and remove both rhgb and quiet and then press enter to boot it. Now you will see all the kernel messages and it will tell you what the problem is.

Oh, and once you get it working, update. CentOS 6.8 is ancient and dates from 2016, nearly 4 years out of date and riddled with high severity security vulnerabilities that are already patched in newer versions. Run yum update and get to 6.10. Also be aware that CentOS 6 has a limited lifespan left and will go completely EOL in about 6 months. You should start planning to migrate to a newer version sooner rather than later.

[azazur]

Dear Sir
Thanks for your prompt response
Please note, i am not an expert in Linux.
while Server starts, before pressing any key the menu disappears and the progress bar starts, we did try several times but did not able to pres any key to enter the garb meu, is there any other way to enter the garb menu?

[TrevorH]

You've got to be quicker then, and no, there's no other way.

[jlehtone]

XEN ... a VM? A VM with its files stored in some image?

It should be possible -- somehow -- to mount filesystem from such image and edit the GRUB menu to (a) increase the menu timeout and (b) edit the kernel command line to get rid of the rhgb quiet.

[azazur]

i am now in that screen
what i have to do do from here, please advice me step by step

[TrevorH]

Press 'e' to edit the highlighted entry, if required scroll to highlight the 'kernel' entry on the next screen then press 'e' again to edit that. Scroll along that line and find where is says 'rhgb' and 'quiet' and delete them then press enter to boot up.

[azazur]

Hi sir
I did edit Kernel line and delete rhgb' and 'quiet words then press enter and it get back to previous page then press b and the attached screen now displaying in console and now stuck here
please advice what next

Thank you very much for your prompt help

[azazur]

present screen

[azazur]

Can anyone tell me what is the problem and how can i get read of that problem ?