Grub2 - Not all OS are found

[cr1zz]

Hey all,

I've installed a multi OS system and I use GRUB as my bootloader.
Unfortunately it doesn't recognize all installed OS.

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root@Test-Linux-Mint:~# os-prober
/dev/sda1:Windows 8:Windows:chain
/dev/sda7:Ubuntu 18.04 LTS (18.04):Ubuntu:linux
/dev/sda8:CentOS Linux 7 (Core):CentOS:linux

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root@Test-Linux-Mint:~# fdisk -l
Disk /dev/sda: 477 GiB, 512110190592 bytes, 1000215216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x7ff95213

Device     Boot     Start        End   Sectors   Size Id Type
/dev/sda1  *         2048     206847    204800   100M  7 HPFS/NTFS/exFAT
/dev/sda2          206848  163842047 163635200    78G  7 HPFS/NTFS/exFAT  	// Windows 7
/dev/sda3       163842048  327682047 163840000  78,1G  7 HPFS/NTFS/exFAT	// Windows 8
/dev/sda4       327684094 1000214527 672530434 320,7G  5 Extended
/dev/sda5       327684096  405807103  78123008  37,3G 83 Linux				// Mint
/dev/sda6       992215040 1000214527   7999488   3,8G 82 Linux swap / Solaris	// SWAP
/dev/sda7       405809152  483932159  78123008  37,3G 83 Linux				// Kubuntu
/dev/sda8       483934208  565854207  81920000  39,1G 83 Linux				// CentOS
/dev/sda9       565856256  649742335  83886080    40G 83 Linux				// OpenSuse

Partition table entries are not in disk order.

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Number  Start   End     Size    Type      File system     Flags
 1      1049kB  106MB   105MB   primary   ntfs            boot
 2      106MB   83,9GB  83,8GB  primary   ntfs
 3      83,9GB  168GB   83,9GB  primary   ntfs
 4      168GB   512GB   344GB   extended
 5      168GB   208GB   40,0GB  logical   ext4
 7      208GB   248GB   40,0GB  logical   ext4
 8      248GB   290GB   41,9GB  logical   ext4
 9      290GB   333GB   42,9GB  logical   btrfs
 6      508GB   512GB   4096MB  logical   linux-swap(v1)

What can I do?

Thanks in advance.

[Mark Phelps]

Actually, with all the Windows installs on sda -- the unfortunate answer is -- not really much, at all.

Your Windows is set to boot from sda1 -- and in there, you would find boot loader that handles both Win7 and Win8.

If you had separate drives, you could have a different Windows OS on each drive, each with its own boot loader and GRUB would then not only see them both, it would create separate boot stanzas for each.

But with them on the same drive, it only sees sda1.

When you then choose Windows, you should get an OS menu in Windows allowing to choose between Win7 and Win8.

[cr1zz]

Hi Mark,

thanks for yaour answer. Ok, I understand the problem with windows. Is it possible to manually add entries for sda2 (Windows 7) and sda3 (Windows .
And why is openSuse (sda9) not recognized?

Thanks in advance.