Arch Linux

jLuca

Member

From: Italy

Registered: 2016-12-06

Posts: 24

[SOLVED] Confused about partitioning dualboot

The output of fdisk is:

Disk /dev/sdb: 232.9 GiB, 250059350016 bytes, 488397168 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: gpt
Disk identifier: 7AD53548-D342-4BB7-A525-828549A4B02D

Device       Start       End   Sectors   Size Type
/dev/sdb1     2048    923647    921600   450M Windows recovery environment
/dev/sdb2   923648   1128447    204800   100M EFI System
/dev/sdb3  1128448   1161215     32768    16M Microsoft reserved
/dev/sdb4  1161216 488396799 487235584 232.3G Microsoft basic data

I have read from the wiki that the suggested size for the EFI partition is "512 MiB or larger" and the Windows EFI partition is currently 100 MiB sizes. I would like to ask if, using the same partition for dualboot Arch and Windows:
1) Should I extend the EFI partition to 512+100 MiB or it's 512 MiB enough?
2) Windows utility won't let me expand it. Should I try with linux ones? like gparted?
3) The wiki says the Microsoft reserved partition is about 128 MiB large. Mine is 16 MiB. Is it normal?

Last edited by jLuca (2017-07-14 01:04:54)

Scimmia

Fellow

Registered: 2012-09-01

Posts: 12,419

Re: [SOLVED] Confused about partitioning dualboot

The size of the ESP doesn't matter that much. If you're using it as /boot, it needs to be large enough to hold the kernel/intiramfs images, but that's the only major requirement. If you're not using it as /boot, it just needs to be large enough to hold you bootloader, which is pretty small.

Don't worry about the MSR.

jLuca

Member

From: Italy

Registered: 2016-12-06

Posts: 24

Re: [SOLVED] Confused about partitioning dualboot

What about the fact that Windows utility won't let me expand the ESP? Should I worry about it or should I just use fdisk or gparted to expand it?

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: [SOLVED] Confused about partitioning dualboot

Don't know much about Windows (maybe it can't resize FAT partition?). Anyway, you don't need 512 Mb. Windows typically occupy only 40Mb and you need an additional 40Mb for Linux if you use it as /boot. If you use a boot manager like refind and put your /boot on another partition, it just needs a negligible amount of space (less than 1Mb if you use it in text-only mode). As for the Microsoft reserved, I Have 16M too, it was created by Windows, I suppose it knows what it was doing (these requirement change from version to version).

If I were you, I wouldn't touch it. Especially that it is very easy to render Windows unbootable and fixing it often mean reinstall.

Last edited by olive (2016-12-19 20:33:45)

jLuca

Member

From: Italy

Registered: 2016-12-06

Posts: 24

Re: [SOLVED] Confused about partitioning dualboot

Ok, thanks for your answers. I will mark this as solved as soon I will install Arch and solve this.

jLuca

Member

From: Italy

Registered: 2016-12-06

Posts: 24

Re: [SOLVED] Confused about partitioning dualboot

I installed Arch successfully without touching the Windows partitions, marked as solved.