Live usb persistence over 4GB

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linmint0001
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Live usb persistence over 4GB

Postby linmint0001 » Fri Nov 17, 2017 4:27 pm

I hope it is OK to post this question here. If not, I apologize, being a complete newbie to linux and this forum...

Thank you so much for this tutorial. I have been following it to create a live usb with persistence over 4GB. I have succeeded in making a persistent usb with linuxmint-18.2-cinnamon-64bit. Persistence is working fine (files are saved, changes to desktop are maintained, etc.) but overall everything works slowly: the persistent usb takes double the time to boot compared to a live usb, and while in a live usb the programs open instantaneously, in the persistent usb it can take up to 30 seconds or more for the same programs to load. I am wondering if this is to be expected or if I might have done something wrong. Using a live linux mint usb (Sarah), I used GParted to create two partitions: a 3Gb FAT32 partition and an 11Gb Ext2 partition named casper-rw. I followed the instructions for using Multisystem but after writing "persistent" and hitting the Backup button, I got the following error:

grub-probe: error: failed to get canonical path of '\cow'.
Installing for i386-pc platform

After that I restarted the system with the persistent usb. However, when the persistent usb is booting, I also see an error message:

error: file '/boot/grub/x86_64-efi/vbe.mod' not found
error: file '/boot/grub/x86_64-efi/biosdisk.mod' not found

Any help would be greatly appreciated!
Last edited by WharfRat on Fri Nov 17, 2017 4:43 pm, edited 1 time in total.

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pbear
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Re: Live usb persistence over 4GB

Postby pbear » Sat Nov 18, 2017 12:29 am

Let's start with something basic. Are you using a 3.0 flash drive on a 3.0 port? If either of those is 2.0, read-write will be much slower.

Relatedly, is the host machine UEFI or BIOS? Stated a little differently, is the host running Win7 or Win8/10?

Finally, is the persistent drive merely for testing or do you intend it to be your long term Mint system?

Can't help with the error messages.
Time flies like an arrow. Fruit flies like a banana.
Running Mint 18.3 Mate 64 bit (by upgrade from 18.1-2)

linmint0001
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Re: Live usb persistence over 4GB

Postby linmint0001 » Sat Nov 18, 2017 10:16 am

pbear wrote:Let's start with something basic. Are you using a 3.0 flash drive on a 3.0 port? If either of those is 2.0, read-write will be much slower.


I am using a 2.0 flash drive on a 3.0 port. I have used this flash drive to run a live version of Linux Mint 18 and it was not slow at all.

pbear wrote:Relatedly, is the host machine UEFI or BIOS? Stated a little differently, is the host running Win7 or Win8/10?


The host machine is UEFI. It is a MacBook running OSX - Yosemite

pbear wrote:Finally, is the persistent drive merely for testing or do you intend it to be your long term Mint system?


At the moment, the persistent drive is more for testing than a long term system, although I would expect it to be my long term system in the long run (I need to feel more comfortable with Linux). Right now I need the persistence to keep the wi-fi and display settings and to install a couple of programs that run on Linux. The FAT32 partition will be used to transfer small documents (pdfs, a couple of pictures) to Mac or Windows machines.

Thanks a lot for your help pbear!

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pbear
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Re: Live usb persistence over 4GB

Postby pbear » Sat Nov 18, 2017 1:09 pm

Many users have reported 2.0 persistent drives as being frustratingly slow, which is why I asked the question. The reason they're slower than a simple live session is that the latter holds everything in RAM. You'd get the same performance from an optical disc, although it would take much longer to load at start-up. By contrast, the persistent drive is swapping stuff in and out of RAM. If it didn't, there'd be no reason to use one.

If you have no plan to dual install Linux, I'd suggest you look into full install to an external hard drive (SSD or conventional). It's a bit tricky on a UEFI machine, as a bug in the installer will modify the internal boot loader even if you specify grub install to the external drive. There are a couple of strategies to get around this, but I don't know whether they work on a MacBook. Does it offer BIOS boot as a compatibility mode? Both strategies I have in mind (here and here) entail installing in BIOS mode, though the external will boot thereafter in UEFI. Alternatively, you could set up the external hard drive as BIOS boot only, which is easy to install but not as convenient to use.

Otherwise, the obvious solution is to get a 3.0 drive. I'd still recommend a hard drive, as flash drives aren't really engineered for this (they're designed for storage) and wear out relatively quickly (numerous reports in the several months range), but a flash would be adequate for light use. Probably some way to transfer your existing install over, but I suspect it's more complicated than merely copying A to B. Or maybe you just want to do over to deal with the grub errors. Yet another option, by the way, which entails another leaning curve but no new equipment, would be to install Mint in VirtualBox. That's a free download and there's an OS X version. Mint in a VM isn't perfect, but good enough for dabbling.

All that said, if you're merely playing around and don't want to invest more time or money, the 2.0 drive you have now will give you a pretty good idea of how Mint works. Just don't hold the slow speed against it.
Time flies like an arrow. Fruit flies like a banana.
Running Mint 18.3 Mate 64 bit (by upgrade from 18.1-2)

fabien85
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Re: Live usb persistence over 4GB

Postby fabien85 » Sun Nov 19, 2017 9:35 am

Macs are a bit different in the sense that you dont have any interface to manage the firmware/BIOS.
Some of the older macbooks cannot boot an external drive (USB stick, hard drive, SSD, doesnt matter) in Legacy/BIOS mode.
If you plan to use your linux USB only on Macs or PCs that came with windows 8 or 10 pre-installed, you can completely disregard Legacy/BIOS mode and only care about UEFI (which will make it a bit simpler).
Legacy/BIOS is to be compatible with PCs that came with windows <= 7 pre-installed.

Agreed with pbear, USB 2.0 is slow, Linux will run much faster though USB 3 (or even better if installed on the internal drive). It would be the same if you were running macOS or windows on a USB 2 drive.

One way not to care about the bootloading is to intall refind on the Macbook, using the macOS install instructions adding the --alldrivers option to the install script : ./refind-install --alldrivers.
This has at least two benefits : it will allow to boot any bootable external drive, and will give easy access to macOS boot modes which are useful in case of emergencies (e.g. boot in 32-bit, safe mode, single user mode, apple hardware test if it's installed, recovery partition if you have one). It can also later serve as your boot manager if you decide to have a dual-boot on the machine.

Indeed virtualbox can be helpful too. Should be faster than through USB2 (though not as fast as a real install), and you can try many different distros that way. Another virtualization option on macOS is Parallel desktop, it's said to be faster and smoother than virtualbox, but it's not free.

linmint0001
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Re: Live usb persistence over 4GB

Postby linmint0001 » Sun Nov 19, 2017 2:16 pm

Thank you both so much for your detailed answers, I really appreciate the time you have taken to help me out. I will look into the various options you suggested and see what works best for me. Again, thank you!

martyfender
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Re: Live usb persistence over 4GB

Postby martyfender » Tue Nov 21, 2017 12:30 pm

Although I haven't setup a Mac with Window since the Lion days, I am wondering if BootCamp would also be another option to setup Windows.
That is, if a BootCamp setup will boot from usb, not sure about that? Maybe someone else with recent experience can chime in.

I am running a USB 3.0 capable, SanDisk Ultra, 32gb drive with persistence from a USB 2.0 port and it runs very well and also very fast. With my setup I am using approximately 26gb of the drive. Space has to be left for the Linux Mint Mate ISO.
I used Universal USB Creator in Windows to create a persistent drive larger than 4gb. I am also running the light weight, Linux Mint Mate 18.1, updated to 18.2 through the update manager. It, however, still boots from the 18.1 ISO.

The way to do this is not even well documented on UUI's site. The way to create a persistent caser-rw with it over 4gbs is to firt format the drive as NTFS. This allow a persistent drive larger than the usual, fat32, 4 gb limit.
The program will take a very, very long time to create 1-2 hours. The first time I tried it it failed to boot because I had not left enoungh free space on the drive for the UUI installer to copy the Linux Mint Mate ISO to the drive and the installer will give no error in this regard.

This all may be a moot point if the BootCamp bios will not boot from USB. On older Macs the BootCamp bios was legacy, if I am not mistaken. However newer Macs I believe, use UEFI bios in BootCamp.

I realize that this would take up extra drive space to run BootCamp and install Windows, but I am offering it as one possibility that may work.


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