Coexistence of Centos on Ventoy and Reserved Partitions

[nguyen ha thai trong]

I think I still have to follow Steve2926's instructions.
If the USB drive no longer boots to Ventoy then Ventoy may not work because Ventoy checks the MBR for Ventoy boot code which has been replaced by Centos.
You need to run the Ventoy Update process so it installs the Ventoy boot code so that it boots to Ventoy.
Then from the Ventoy menu you should be able to boot to Centos on partition 3.

[Steve2926]

Maybe try

### BEGIN /etc/grub.d/10_linux ###
menuentry "Ventoy" --class=custom {
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_gpt
insmod xfs
insmod fat
search --set=root -f /ventoy/ventoy.cpio
chainloader (${root})/efi/boot/grubx64_real.efi
}

[nguyen ha thai trong]

Step 1: Update ventoy, don't worry because it won't lose existing data, just replace mbr
       
Step 2 :
In a similar topic:
使用gurb2 启动 ventory


Longpanda advised:

对于 Legacy BIOS 模式:
chainloader (hd1)+1
boot

对于 UEFI 模式:
chainoader (hd1,2)/efi/boot/grubx64_real.efi
boot