Switch From CachyOS (limine,btrfs), keep dual-boot | Linux Mint Community🍵 | Page 1

peak sequoia Aug 30, 2025, 5:53 PM

#

I'm going to switch back to Linux Mint after trying out CachyOS, and I'm a bit unsure how to partition my drive, I installed CachyOS with limine bootloader and on a btrfs partition alongside Windows (After many failed attempts it's a miracle Windows still boots), I want to switch back to grub (and would it be wise to keep mint on btrfs?) I'm not sure how to remove all the CachyOS partitions and install mint in that free space.
Which of these partitions are necessary for the windows side to work and which are safe to delete?
(I should've been wiser to take a screenshot of my partitions when I switched from Mint to CachyOS)

silent kindle Aug 30, 2025, 6:19 PM

#

You have dual ESPs, which meay be problematic. You should just remove the BTRFS one and then install Mint, tell it to install alongside Windows. If you encounter issues, share screenshots.

peak sequoia Aug 30, 2025, 6:24 PM

#

I think CachyOS installed its own ESP :/ I had lots of trouble with that install.
I'll give it a try, I know Mint has issues with multiple ESPs.
If I remember correctly the 2GB one is the one Cachy installed, I'm tempted to just wipe that and leave the 100MB one.

silent kindle Aug 30, 2025, 6:25 PM

#

If the second ESP gives you trouble, remove that as well. But first make sure it's the one without the Windows loader.

#

Also, if you are fiddling with multiple operating systems on one drive, don't hesitate to call the actual expert, Stunner. Not my area of expertise.

peak sequoia Aug 30, 2025, 6:27 PM

#

Heh, I'll give it a try, it's not a huge problem if I break it.

#

Thanks thumbsup

#

I think I figured something out, I checked limine.conf and saw the GUID of the EFI partition for Windows
And I did a lsblk to find that indeed the first one is the Windows one

silent kindle Aug 30, 2025, 6:55 PM

#

Then you should probably remove the other ESP.

peak sequoia Aug 30, 2025, 7:08 PM

#

I'm not able to install grub, first I tried to have a 500MB EFI partition for Mint and install grub on that. On my 2nd try I didn't make that 2nd EFI for Mint and picked the whole drive as the target for the bootloader.

flat sand Aug 30, 2025, 7:44 PM

#

you're NOT SUPPOSED TO MAKE multiple EFI partitions on a single drive!

#

just wipe what's not needed from your old thing and tell Mint installer to use the 'install alongside Windows' option

#

100 MB is the typical size for ESP that Microsoft makes (prior to the very latest builds of Win 11)

#

it's fine if it's shared.

silent kindle Aug 30, 2025, 7:48 PM

#

flat sand you're NOT SUPPOSED TO MAKE multiple EFI partitions on a single drive!

Welcome, Stunner. I knew this would be your first reply.

peak sequoia Aug 30, 2025, 7:56 PM

#

Hello PikaWave
I was troubleshooting, the reason it wasn't working was the 100MB EFI partition was full, I managed to install grub manually, but update-grub isn't seeing my windows install

#

CachyOS put some files there so I deleted them to free some space, but now I can't get grub to see Windows, even though the Windows bootmanager and my windows partition are intact

peak sequoia Aug 30, 2025, 8:00 PM

#

flat sand you're NOT SUPPOSED TO MAKE multiple EFI partitions on a single drive!

I know this much from all the online searching, but the CachyOS install was troublesome and it ended up with two EFI partitions 😩

silent kindle Aug 30, 2025, 8:04 PM

#

When in doubt, extend the ESP instead of making another. With multiboots, it can get cramped in 100MB.

#

Windows 10 in its early builds also famously undersized the ESP, which caused a known issue with some update years later.

peak sequoia Aug 30, 2025, 8:05 PM

#

In hindsight, the size was probably the issue with CachyOS too, I just didn't realize it at the time

silent kindle Aug 30, 2025, 8:07 PM

#

That information is annoyingly hard to come by.

flat sand Aug 30, 2025, 8:07 PM

#

can't extend Fat32

peak sequoia Aug 30, 2025, 8:08 PM

#

I'll reboot and start over and do a clean install now that I have enough space on EFI, it should work as it always does

flat sand Aug 30, 2025, 8:08 PM

#

if the Windows system is totally UEFI-run then u can use a technique by CyberCPU Tech

#

which involves using the Windows Install DVD/ISO to rebuild the Windows EFI from complete empty.

#

I think it only takes up 20 MB if even. and GRUB takes up about 30 MB

peak sequoia Aug 30, 2025, 8:09 PM

#

I'm at 50MB with Grub + Windows after deleting the CachyOS stuff

flat sand Aug 30, 2025, 8:10 PM

#

pretty much my estimate exact

peak sequoia Aug 30, 2025, 8:10 PM

#

I'll try a mint install after a reboot and if that doesn't work I'll try your suggestion

silent kindle Aug 30, 2025, 8:17 PM

#

flat sand can't extend Fat32

Iirc, Windows can. It is part of the workaround for that old Win10 issue.

flat sand Aug 30, 2025, 8:18 PM

#

oh. I thought it just wasn't a supported filesystem feature. Only going by gparted's info

silent kindle Aug 30, 2025, 8:21 PM

#

flat sand oh. I thought it just wasn't a supported filesystem feature. Only going by gpart...

GParted is a stickler for best practices. Microsoft tends to just make things happen if they want something.

#Switch From CachyOS (limine,btrfs), keep dual-boot