2nd OS not listed in Grub2 menu after Fedora install

hrsetrdr · 10-17-2018, 06:43 PM

2nd OS not listed in Grub2 menu after Fedora install

Haven't had this happen in years. Install Fedora and all well except CentOS 7 is not listed in Grub menu. I thought that

Code:

os-prober

, then

Code:

grub2-mkconfig -o /boot/grub2/grub.cfg

would fix the issue, but upon reboot CentOS is still not listed.

Running "fdisk -l" :

Code:

Device     Boot     Start       End   Sectors  Size Id Type
/dev/sda1  *         2048 136796159 136794112 65.2G 83 Linux
/dev/sda2       136798206 156327935  19529730  9.3G  5 Extended
/dev/sda3       156327936 293046271 136718336 65.2G 83 Linux
/dev/sda5       136798208 156327935  19529728  9.3G 82 Linux swap / Solaris

...shows Centos 7 at /dev/sda3. Dumb question: should /dev/sda3 be flagged "bootable"?

syg00 · 10-17-2018, 07:02 PM

Did it show up in the os-prober run ?.
Grub ignores the boot flag - that is merely a hangover from MS-DOS that M$oft, and some BIOS writers, still think is needed.

Bolding your entire post is pointless.

frankbell · 10-17-2018, 07:07 PM

Quote:

Dumb question: should /dev/sda3 be flagged "bootable"

That should not be necessary.

I'd suggest trying an update-grub. http://manpages.ubuntu.com/manpages/...te-grub.8.html

hrsetrdr · 10-17-2018, 07:08 PM

Quote:

Originally Posted by syg00

Did it show up in the os-prober run ?.

No, only shows:

Code:

/dev/sda3:Fedora 28 (Twenty Eight):Fedora:linux

Quote:

Originally Posted by syg00

Bolding your entire post is pointless.

Sorry if the bolding bothers you, not sure why.

syg00 · 10-17-2018, 07:37 PM

os-prober is just a script, and looks for "known" patterns for kernel names. I would be surprised if CentOS didn't conform.

John VV · 10-17-2018, 07:57 PM

in the past on fedora i found that forcing a kernel update solves this issue
-- the needed scripts are then ran

Code:

dnf -f update kernel*