Urgent, No Permissions to edit grub file

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eliasfar
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Urgent, No Permissions to edit grub file

Post by eliasfar » 2017/04/25 17:59:34

Hi Centos fans,

Since I encounter panic screen then I am trying to edit my grub file following this link instructions:
https://bugs.centos.org/view.php?id=9860

But I am unable to edit th grub file by live or installation cd anymore. e. g. when I go into folder etc/default folder through livecd, I can open the grub file but I have no permission to edit it and add the recommended line. Is there any workaround for this? since I am new to centos that would be great to benefit your assistance. Thanks

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avij
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Re: Urgent, No Permissions to edit grub file

Post by avij » 2017/04/25 19:53:57

Try booting from your hard disk instead of a CD/USB. When you boot, you are presented with a choice of kernels to boot. Hit 'e' to edit the boot parameters. Once you are happy with the boot parameters, hit 'b' to boot the system with the updated parameters. This should let you boot normally. Once you have booted normally, you should be able to edit grub config, so that you wouldn't need to do this change manually every time you boot.

eliasfar
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Re: Urgent, No Permissions to edit grub file

Post by eliasfar » 2017/04/25 20:10:14

avij wrote:Try booting from your hard disk instead of a CD/USB. When you boot, you are presented with a choice of kernels to boot. Hit 'e' to edit the boot parameters. Once you are happy with the boot parameters, hit 'b' to boot the system with the updated parameters. This should let you boot normally. Once you have booted normally, you should be able to edit grub config, so that you wouldn't need to do this change manually every time you boot.
Special thanks for reply avij, I have tried booting from disk but since it resulted in panic screen crash I switched over livecd. But I tried to do your suggestion, few things are confusing for me. I press 'e' (as done in past) on the kernel but I don't know where to add the the command 'initcall_blacklist=clocksourse_done_booting'. Also are you sure about 'b' to boot? I am so confused.

owl102
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Re: Urgent, No Permissions to edit grub file

Post by owl102 » 2017/04/25 20:31:33

I must confess that I don't understand the main problem. AFAIK this is a problem which only occured with CentOS 7.2. Neither 7.0 nor 7.1 nor 7.3 do have this problem.

So if you had installed an older version (7.0 or 7.1) and are now getting trouble after updating to 7.2, the solution is easy: Boot an older kernel (from 7.0 or 7.1) and update your system afterwards to 7.3.

If you are trying to install from scratch, the solution is even more simple: Don't try to install 7.2 but install 7.3 instead.
German speaking forum for Fedora and CentOS: https://www.fedoraforum.de/

eliasfar
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Re: Urgent, No Permissions to edit grub file

Post by eliasfar » 2017/04/25 20:43:04

owl102 wrote:I must confess that I don't understand the main problem. This is a problem which only occured with CentOS 7.2. Neither 7.0 nor 7.1 nor 7.3 do have this problem.

So if you had installed an older version (7.0 or 7.1) and are now getting trouble after updating to 7.2, the solution is easy: Boot an older kernel (from 7.0 or 7.1) and update your system afterwards to 7.3.

If you are trying to install from scratch, the solution is even more simple: Don't try to install 7.2 but install 7.3 instead.
Thanks owl102 for this reply. It was extremely helpful, I honestly installed 7.2 from scratch because the program I need to install (autodesk flame) is just compatible with 7.2 1511. So I installed 7.2 1511 from scratch, playing around this problem really made me tired, so I am gonna try your vluable suggestion and install 7.3, but I am not sure if I can run autodesk flame on 7.3, if there is any workaround on how to install a 7.2 1511 compatible software on e.g. 7.3 I am honestly unaware of it. You helped me so much friend, but if you'd have any suggestion about this problem as well, that would be my pleasure. Bests,

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avij
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Re: Urgent, No Permissions to edit grub file

Post by avij » 2017/04/25 22:15:36

I agree that you should primarily try to use 7.3 instead. Besides, 7.3 is what you get when you run a regular "yum update" on a 7.2 system. There is a very good chance that the application will work with 7.3.

In case you still want to try with 7.2, I'm sorry, my above instructions for modifying the parameters were for CentOS 6 and earlier. CentOS 7 is different in this regard. I forgot that, because it has been ages since the last time I had to change these parameters on CentOS 7. You should hit 'e' to enter the boot parameters, then scroll down where you see "linux16 /vmlinuz-3.10.0.---" and then add the new parameter to the end of that line. Note that the line is long and continues on the next row. Once you are done, hit Ctrl-X to boot.

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