【Solved】How to mount ventoy partition ?

[longpanda]

Currently you can't mount /dev/sdb1 rw.  Because a device mapper is created based on the ISO files in sdb1, and this will make /dev/sdb1 readonly and busy.
If you just want to write or save something into the USB you can wait for the next release.
In the next release, you can reserve some disk space when installing Ventoy. After that you can make /dev/sdb3 /dev/sdb4 with the reserved space and you can mount them as you want in the live system.

This is something I asked in my other post, there is in fact some impediment for Ventoy (like redo a lot of code) not to mount the primary partition (from where the ISO is being read) as read-write and keep it busy so that it is not possible for the user to umount it? As I said, G2FM works like this and it works well

Ventoy is different from G2FM in internal mechanism, goals and usage scenarios.

For many distros like rhel/centos/arch/Fedora...   G2FM must and can only use partnew to boot them.
partnew is simple and useful but also has many limitations, for example:
1. The file must be contingous in the disk
2. The disk can NOT be write protected
3. The distos must accept the partition created by partnew
4. You can't create 4 partition in the disk (or partnew will fail)