Coexistence of Centos on Ventoy and Reserved Partitions

[xk-devops]

I have Ventoy and CentOS_7 on different media and everything works. Relative to my system.


1.

When you turn on the computer, by default, the CentOS_7 menu is loaded in UEFI mode. To add the "start VENTOY" item to the CentOS_7 menu, write to the "sdb2/boot/efi/EFI/centos/grub.cfg" file (I have a CentOS_7 boot sector on sdb2, you probably have sdb3):

In the file "sdb2/boot/efi/EFI/centos/grub.cfg" write:

Code:

menuentry 'CentOS_7 Linux' --class centos
......
}
......
### BEGIN /etc/grub.d/30_os-prober ###

  menuentry "start VENTOY" --class ventoy {
        search --set=root -f  /ventoy/ventoy.cpio;
        chainloader (${root})/efi/boot/BOOTx64.efi;
        boot;
  }

2.

To start CentOS_7 from Ventoy menu by "F6":

a)
Find the UUID of the CentOS boot sector (you probably have sdb3): ls, blkid, lsblk...
For example, we enter the command: 

Code:

lsblk -o  +uuid,LABEL,PARTLABEL,model

System response:

Code:

[root@localhost ~]# lsblk -o  +uuid,LABEL,PARTLABEL,model
NAME              MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT                  UUID                                   LABEL        PARTLABEL                    MODEL                                                     
sdb                 8:16   0 232,9G  0 disk                                                                                                              Samsung SSD 860
├─sdb1              8:17   0   200M  0 part /boot/efi                   3438-B9A1                                           EFI System Partition        
├─sdb2              8:18   0     1G  0 part /boot                       d251a781-25aa-41f4-aft3-d6972bc010db                                            
└─sdb3              8:19   0 231,7G  0 part                             e4vhO5-5ePN-rPof-r77Q-y11x-Txt3-KKZHRm                                          
  ├─centos00-root 253:0    0    50G  0 lvm  /                           d9a6d9e5-d5e0-4bfc-ab98-5ba1dd918aa9                                            
  ├─centos00-swap 253:1    0   7,8G  0 lvm  [SWAP]                      570215de-e3e3-407e-9b1f-41f25b5445bf                                            
  └─centos00-home 253:2    0   174G  0 lvm  /home                       12e67e6d-8af0-42f1-b1e0-0fedfce4a72b

I have CentOS bootloader on sdb2  --  uuid: d251a781-25aa-41f4-aft3-d6972bc010db

b)
In the file "/ventoy/ventoy_grub.cfg" or "/grub/grub.cfg" (but it will be in the main Ventoy menu) we write:

Code:

menuentry "  start grub.cfg CentOS" --class  centos{
    insmod gzio
    if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
    insmod part_gpt
    insmod ext2
    search --no-floppy --fs-uuid --set=root d251a781-25aa-41f4-aft3-d6972bc010db
    configfile /grub2/grub.cfg
}

Thank you very much. I will try and see according to the method you provided. Thank you very much again