Confused about the boot partition

[Antarmanu71]

This is not a problem per se, but it confuses me and I think I see this kind of thing for the first time.

Yesterday I installed new Manjaro Xfce installation on disk sda1. There were also previous installations of Manjaro present on this laptop, namely on sda2 and sda4. I distinctly remember that I installed this latest OS on sda1 because it used to be ntfs and I formatted it as ext4 for Manjaro.

While the OS is booting, it writes that it is booting from sda1. However, if I type sfdisk -l in terminal, it shows sda4 as the current boot partition:

$ sudo sfdisk -l
[sudo] password for blueflame71: 
Disk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: ST1000LM024 HN-M
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: 0x32774d96

Device     Boot      Start        End   Sectors   Size Id Type
/dev/sda1             2048  496197631 496195584 236.6G 83 Linux
/dev/sda2        496197632 1212997631 716800000 341.8G 83 Linux
/dev/sda3       1212997632 1264197631  51200000  24.4G 82 Linux swap / Solaris
/dev/sda4  *    1264197632 1953523711 689326080 328.7G 83 Linux

Gparted also shows that sda4 is the boot partition:

Interestingly, Gparted says that sda4 is not mounted. So how can an unmounted partition be the one from which the current OS is booted? Could someone please clarify this for me?

[Wollie]

What you see is only the Boot flag which does not matter at all for BIOS boots by grub (using msdos parted disk). This is only relevant for Windoze BIOS installations. So everything is fine. You could assign the boot flag to whatever partition - it does not chang anything in your case.

BIOS boot means, your system boots through settings in MBR (boot.img) and core.img. See here for more details:

GNU GRUB