Dual Boot two Linux distro

He will install CentOS on the Windows C drive I think. Because he want to replace Windows entirely. Actually a separate /var is a good choice because that’s what consuming the biggest space in the entire / partition. :slight_smile:

yep, maybe it was fine ten years ago, but imho (except on chrome/cloudbook with eMMc or stuff like that) with actual DD size on laptops, i’ll always focus on simplicity (remember manjaro quote !) of partitioning instead of consuming space, especially for a newbie & without windows inside… :slight_smile:

Well, first, thank everyone.

But Now i got a big trouble.

Seem that i couldn’t find a way to Stop CentOS 7 installer to install GRUB.

So when i installed CentOS, try to mount it on sda1, now the disk partition is like:
sda1 / CentOS
sda4->Extended partition
sda5 /var
sda6 /boot
sda7 /
sda8 /home
sda9 linux-swap

I mount the /boot, /var and /home, share them with CentOS.
When i use CentOS installer, it install GRUB2, actually GRUB2 find Manjaro.

But after i try to boot into Manjaro, it comes Kernel panic, the message is

not syncing: VFS: Unalbe to mount root fs on unkown-block(0,0).

I can boot in CentOS by using the new GRUB, but can not boot in Manjaro.

So what should i do now…

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It would have been a good idea to ask on CentOS forum how to do that.

Now visit wiki.manjaro.org and search how to repair Grub.

Can you boot into CentOS? If you can, you can repair your grub from there. But I don’t know if CentOS has update-grub command by default, so the command will be sudo grub-mkconfig -o /boot/grub/grub.cfg
If it shows you the same output like above (root fs error), you might need to chroot into Manjaro whether by Live media or in CentOS but it will need a lot of knowledge to do so. So just try the command above first. :slight_smile:

It doesn’t has anything to do with HDD size. It’s basically the same as having separate /home and /boot partition. Some might say it’s easier for newbie to not having it at all, but it will make life easier if you want to reinstall without losing your data. :slight_smile:
So it’s something optional depending on what the user prefer. But I used to have it because I used to have a slow internet speed, so I don’t want to redownload all the packages when I want to reinstall my system. So maybe the OP has the same reason as me? He doesn’t seem like a complete newbie for me though. At least he knows how to partition his HDD to his liking :slight_smile:

Actually, I am going to chroot into Manjaro by using the Manjaro Live USB.
And following the Wiki to restore grub:

Do i need to format the /boot partition?

Does Manjaro use GRUB2, because when i install CentOS, it give me a GRUB2.

A good idea to go with Manjaro Wiki as you hardly find any CentOS user on a Manjaro forum who could tell you exactly how to do it the RedHat way.
No, you shouldn’t need to format /boot partition any yes Manjaro uses Grub2.

You don’t need to format it. Just do what the wiki told you to. Yes, Manjaro is using grub2.
@eugen-b beats me to it, damn :smile:

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The new forum sucks again :wink: :imp: The old gave you notifications if s.o. wrote s.th. why you were typing. :stuck_out_tongue:


Similarly it is good to know which gurus are online! :grinning:


Or their current wiki page. :wink:

1 Like

Thank for comment, :slight_smile:
Well, i bring my GRUB and Manjaro back.

But i couldn’t use the GRUB boot into CentOS now… Damn.
Show Kernel panic again -> not syncing: VFS: Unalbe to mount root fs on unkown-block(0,0).

So I try to reinstall CentOS again.
Now i want to ask, How can i clean up the useless configure file of /boot ??

Sorry about that, maybe CentOS folks will be able to help you.

That’s easy: run sudo update-grub on Manjaro again after having formated your CetOS partition.
But maybe some hardcore troubleshooting might resolve the issue so you wouldn’t need to reinstall…
A reinstall is unlikely to solve anything here, because it probably would run the same way as the first time.

Well, after i delete CentOS partition, and run update-grub, reboot.
GRUB would not find CentOS now, but the old linux image and initrd image still in /boot.
How can i clean up the useless image in /boot??


sudo rm /path-to-file should do

Maybe this will help: https://bbs.archlinux.org/viewtopic.php?id=199710
You don’t need to remove images from /boot. A simple sudo mkinitcpio -P will rebuild all kernel images and update them if they’re already there.

As a newbie I always use Grub Doctor to repair Grub.
I have a liveCD of PartedMagic (the last free edition; free as a free beer!) which I use to restore Grub.
it’s easy as just a few clicks.

Finally, I can use Manjaro grub2 boot into other Linux distros now.
And they seems running correctly.

But last question is that, i got some Failed message while booting into fedora.

> @localhost ~]# journalctl -ab | grep Failed

Jul 13 23:40:01 localhost systemd[1]: Failed to start Load legacy module configuration.
Jul 13 23:40:01 localhost systemd[1]: fedora-loadmodules.service: Failed with result ‘exit-code’.
Jul 13 23:40:04 localhost systemd[1]: Failed to start Show Plymouth Boot Screen.
Jul 13 23:40:04 localhost systemd[1]: plymouth-start.service: Failed with result ‘core-dump’.
Jul 13 23:40:06 localhost systemd[1]: Failed to start Show Plymouth Boot Screen.
Jul 13 23:40:06 localhost systemd[1]: plymouth-start.service: Failed with result ‘core-dump’.
Jul 13 23:40:20 localhost bluetoothd[850]: Failed to obtain handles for “Service Changed” characteristic
Jul 13 23:40:21 localhost systemd[1]: Failed to start Irda Support.
Jul 13 23:40:21 localhost systemd[1]: irda.service: Failed with result ‘resources’.
Jul 13 23:40:22 localhost systemd[1]: Failed to start LSB: Bring up/down networking.
Jul 13 23:40:22 localhost systemd[1]: network.service: Failed with result ‘exit-code’.

Well, seems those message tell me that the setting of Manjaro would not start. it is normal, but why fedora would load the setting of Manjaro?

So i want to ask:
Manjaro modifies its grub due to its implementation of different platform(like intel)??

And how can i check my machine by using systemd?

However, Thank Guys.

What do you mean by Fedora is trying to start Manjaro services? Why do you know they’re Manjaro services? To check your system using systemd, you can start with finding out what’s causing the service to fail. In your case, start with systemctl status fedora-loadmodules.service

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