Using external USB SSD for a full Mint install

Hello! My first post here, and all suggestions welcome.

I have been having trouble doing a full install of Mint 19.1 on an external USB SSD. I have done this successfully on a thumb drive (in fact my current Mint is running on that right now). However - trying to replicate that to put a full install on the external SSD has had various unexpected and somewhat catastrophic results - including the installer replacing the boot loader in my internal hard drive even though I was very sure to choose the external drive for the install.

I have a lot of questions, but first - could it be possible that the SSD can’t be made into a bootable drive and that is why the installer wants to put the boot on the hard drive?

When I did successfully create the thumb drive, I used an old Vista/Mint dual boot laptop and it went fine. This time I tried two different Windows 7-only laptops - and it was the same result each time - needing to restore/repair the boot loader and run a restore from my Macrium backup software.

Here are the boot settings in the BIOS for the one Win 7 laptop:

UEFI/Legacy Boot [both]
-UEFI/Legacy Boot Priority [Legacy First]
-CSM Support [Yes]
Network Boot [PCI LAN:IBAGE]

I’m sure there must be an easy way to do this, but thought my first question should be - is it even possible on the SSD - or does it need to be partitioned ahead of time to avoid the misplaced boot loader issue?

Thanks for any ideas - I’ll be happy to answer questions or post anything that might help.

1 Like

Do you want to have only Mint or dual boot?
If yes, I would turn off CSM and use everything in EFI mode. If you want to keep Windows, it is installed in BIOS mode, so you have to install the new OS in BIOS mode, as well.

I remember that Ubuntu/Mint offers you a specific option, where to install the bootloader to. Sometimes it picks the wrong disk and you have to manually choose the correct one. If you are choosing Something else during the installation, there should be an option below the partition list.

1 Like

Thanks for the reply. I want to have only Mint on the external USB SSD - and not make any changes to my actual laptop. Trying to install to that SSD drive did cause the issue twice on both Win 7 laptops.

I “think” I might still be able to use the old Vista/Mint dual boot laptop to set it up but it is very very slow! I was just starting to think that maybe it just wouldn’t work with that SSD, and in truth, don’t want to risk my Win 7 laptop again.

But I want to be able to boot into that USB SSD and run the full install of Mint from it using my Win 7 laptop, if that makes sense.

So there isn’t anything about the actual external SSD that might be causing the issue?

Thanks again!

That is something I missed when reading the post. The issue is that it is not ideal to put the boot loader on an external medium. I think you could circumvent the issue if you select the external medium as the primary boot device within the UEFI. The issue is, that depending on the UEFI it might reset each time the computer boots without the removable medium. Sometimes it is also unreliable.
I would suggest that you should manage your OS situation by correctly installing the bootloader onto the internal HDD and not trying to avoid it. However I am not sure if the external HDD would be always detected reliably by GRUB2 on your internal HDD.

That said, technically your SSD appears pretty much the same way to your UEFI as a thumb drive does. They are both flash memory based media, connected over USB.

1 Like

OK - so it sounds like using the external USB SSD for my Mint install probably isn’t the greatest idea. I can send it back - so maybe I’m going to do that and look into a reasonably priced refurbished laptop and just do a single Mint install on that instead. Probably a more reliable solution? I know that Dell has many refurbished Win 8.1 laptops, so maybe I could even look into Mint as the primary OS and Win 8.1 in a VM?

I have trying to find some alternatives, since Win 7 is coming to its EOL. I really love Mint and thought I had a good solution with that SSD - but maybe it is a lot of work when another option might be better.

Thanks so much for your help and advice - much appreciated! :slightly_smiling_face:

What do you need Windows for anyway? Seeing your opinion on laptops, I presume you don’t game.

the external part isn’t problematic as far as i know. i have installed a few different distros to my external hdd, but that was with linux on my internal. the issue should be getting the bootloader set in a good place.

somehow this appears to be a bigger issue than i thought. i just did an install from a live usb to a second usb. the pictures below (i believe) clearly show not only that i chose the second usb (sdc) for the bootloader

but also that the installer reported writing it there.

in spite of both of those, after rebooting the system grub on my internal ssd (which should have remained untouched as far as i would have thought) went to a rescue prompt and i had to boot in through the usb’s grub so i could re-install grub to my ssd.

i wouldn’t have imagined there would or should have been any interaction between the two, but just as you said @TNLH even though i know which drive i chose the install did a number on my internal ssd’s bootloader.

1 Like

Hello and thanks for the reply. Thanks for trying this - but I am sorry that it caused the issue it did.

Yes - just as I said - the installer put the bootloader on my sda, not the sdc where I had specified! Is this something to do with the BIOS possibly? I’ve read that UEFI can cause that, but my laptop boots in Legacy - which I thought was not UEFI.

In any case - while it was installing, I could see it say “looking for other operating systems” shortly after your screenshot above. So even though it was saying it was installing on sdc, it seems that it was also looking for the other OS and installed it there!

Very upsetting - as you said - I got the grub rescue prompt and had to finally use my Macrium Restore USB to get back to my Windows 7, and do a full restore from there. And yes - it should not have touched that system at all!

In any case - I appreciate your trying it and confirming what I saw - but again, sorry it created issues for you. Glad you got it restored!

I think I am done trying to do it this way with an external drive, and will start looking into another laptop!

ETA: I had done this successfully back in the spring and I am running Mint from a full install on USB. So it was possible - not sure why it isn’t now.

Thanks again!

1 Like

Nope - not a gamer! As to Windows - I really like Windows 7, but it is coming to its end of life soon, and I have been looking for alternatives. Mint seems to fit the bill, but a few of my programs won’t run on Mint, so I need a Windows alternative for them. I was thinking of Win 8.1 - more affordable for a used laptop than Win 10 - and still viable for a few more years - and maybe not the update drama surrounding 10.

Thanks for your reply!

1 Like

Make a list of those programs with their respective version number, if significant. Then explain why you specifically need exactly these Windows-only programs.

Well, the main one is my Family Tree Maker program - it syncs with I guess I “need” it since I did pay for it and I use it for a backup for all of my online files. I know there are alternatives, but I have a lot stored in the program already.

As to others - things like Photoshop and a program called Folder Marker that I also bought and don’t want to lose.

I know that I can find alternatives to all these - but with the limited space I now have on my thumb drive install - I haven’t tried any. Thus my thinking of possibly getting a Win 8.1 laptop and setting up Mint and Windows in a VM. Not sure I know enough about that - but sounds like it has possibilities. Thanks!

At first I made a mistake when reading up on Family Tree Maker but here is a beginning of looking for an alternative way of using this software.

As to

you can find a free alternative here.

You can probably run

on Linux, as displayed here.

Luckily prices for thumb drives and flash cards have sunken rapidly in the recent years. You need maybe 30 bucks for a thumb drive with huge space on it.

This is also a good alternative, if the others fail to satisfy one’s needs.

no need for you to be sorry at all :slight_smile: i was hoping i might be able to help find a verified way to make your desired setup work. that’s why i took the screenshots. i was also hoping to have a go at a full usb (thumb drive, not external hdd) installation which i had never tried before.

i (should by now) know better than to make possibly significant system adjustments without a recent backup, but i was sure that since everything went relatively smoothly with my external hdd installations before (i believe it was both lubuntus) that this time would be the same. luckily grub is easy enough to reinstall and there was no harm done. i was simply surprised by the interplay between the drives and bootloaders.

this could be a possibility. my present setup is all uefi, but i turned on both/legacy to create the usb so my system would be similar to the one you are using. my installs to an external hdd in the past were on a bios/legacy system. there certainly are factors at play here which i hadn’t contemplated/run into before.

i remember macrium from my windows days and think it is a solid product even though i only used the free version. i still have a backup image of the win7 laptop i sent mom last year just in case. the ability to create a system-specific rescue usb is quite impressive.

i just recently started playing with vm’s myself and followed this fairly straightforward and well-explained article. because linux mint is based on ubuntu, the terminal commands should work for mint 19 (based specifically on ubuntu 18.04) as well.

edit: to clarify, kvm and virtual machine manager are not the only vm options in liunx. i chose kvm after a little research suggested it was relatively easy to use and integrated into the linux kernel so it didn’t use as many system resources as some other options. i shared this link because it shows that install and management is pretty quick and easy.

1 Like

Thanks so much for the links and the information about possible ways to use my Windows side software! Much appreciated. I will check into those.

Yes - I have several for storage - but wouldn’t I need to have “room” on my thumb drive install to run these programs? When I set this up - it was sort of an experiment, and I used a 64 GB thumb drive. It runs well - but that was my reason for trying to install Mint on the SSD - it is 240GB so there would have been much more room for programs, timeshifts, whatever.

But since I can’t seem to install Mint to the SSD - until I get a laptop to devote to Mint, I only have it on that small 64gb drive.

Yes - I am going to look into it more!

Thanks for the replies and links! :slightly_smiling_face:


Thanks again for giving it a try. It is puzzling since like you - I had done it successfully when I created the thumb drive install I am using - and thought this would be the same. It certainly shocked me when my “precious” Windows 7 laptop was not bootable with the installer situation, but thankfully I could recover and restore it. That was the reason I was wanting to use the USB install - I thought that it wouldn’t touch my Windows system - seemed like all it needed to be was a bridge to put the install from the installer onto the SSD. Live and learn I guess.

Indeed - and glad I had the Macrium backup to fall back on! But to the discussion with Akito above about programs, Macrium is one that I know won’t run on Mint - too bad!

And mine is Legacy, so I’m not sure what is going on. It seems to be behaving like UEFI?? One thing I know - I won’t be trying that again on this laptop for sure.

Thanks for the article and the link. I think this is something I will want to look into further since it would allow me to use the few Windows programs and still have Mint as my main OS. Compared to Windows - Mint just seems to be a much smoother OS. I was really optimistic that having it on that external SSD would give me the best of both worlds - but not with the installer/grub issues.

Thanks so much for all of the ideas and suggestions! :slightly_smiling_face:


installing them does take some space. i have a 4 month old bodhi linux 5.1 (also based ubuntu 18.04) install that takes up just about 25 gb and i’m sure some of that is personal stuff. i also have a mint 18.3 install that i don’t boot into too often that takes up less than 10 gb. so 64 gb should be plenty for a working system.

my install to a 16 gb usb 3.0 usb was successful (minus the grub issues), but it might also be helpful to note that there is a lag in performance when running through usb vs an internal install. at least there was on my system (intel middle of the road i5 with 8 gb ram) :slight_smile:

i keep my timeshift snapshots on an external hdd (in case the internal dies) and they do take up a bit more room (about 50-60 gb at present), but a big part of that is because i am overcautious and keep way more of them than i need to.

i haven’t attempted to run macrium in linux so i couldn’t speak to that, but i use timeshift like you mentioned and feel that it is just as helpful. one of the interesting options that i have never had occasion to try is an offline restore:

Snapshots can be restored either from the running system (online restore) or from another system that has Timeshift installed on it (offline restore).

so if your drive does die and you have snapshots saved elsewhere, all you need is a live cd to install timeshift to then you can install the most recent snapshot to a new drive.

one of the things to keep in mind with timeshift is that it does not backup personal data by default so it is a good idea to have another method to keep track of that.

Thanks for the Timeshift info - more on that later.

Can I ask this? The error message I was getting was this:

error: no such device with the long string of the device name
:unknow file system
grub rescue>

What should the command have been to continue or restore?

Thanks! Will post back later on!

that depends on what you mean by continue or restore.

to get back into windows, you would have needed to fix your master boot record. this link shows how to do that on win7 with an installation dvd. this link shows how to do that on win10 with a bootable windows usb. it has been a while since i have had to rescue a windows partition so i can’t vouch for either of those specific methods, but that is the gist of what you would need to search for and pull off. i used to use the ultimate boot cd, but am pretty sure that was with xp. it has been some time :slight_smile:

when i first started using linux a couple of years ago, i found myself at a grub rescue prompt. this article is a few years old, but the info should hold true since it was for grub 2. at the very bottom where it shows how to set the boot drive, partition and initrd looks similar to what i needed to do to boot back in.