Howto make USB boot drives

[boqsc]

Hey sudodus, I've installed persistent Ubuntu 18.04 using mkusb, but from the first time I did boot up I've got weird temporal background color switches: https://askubuntu.com/questions/1078...lue-background

They do not bother much, but I'm interested in solution or some kind of guideline where I could check for defect that causes these background changes.

Also, it seems that running command sudo update-initramfs -c
Gives me this output:

update-initramfs is disabled since running on read-only media

The strange output appears mentioning that I'm running on a read-only media. But the changes I make to the system are persistent. This is kind of confusing

[sudodus]

Hey sudodus, I've installed persistent Ubuntu 18.04 using mkusb, but from the first time I did boot up I've got weird temporal background color switches: https://askubuntu.com/questions/1078...lue-background

They do not bother much, but I'm interested in solution or some kind of guideline where I could check for defect that causes these background changes.

I think it is a compatibility problem between the graphics driver and and the graphics chip/card at an early stage of the boot process. One way to 'get rid of it' should be to turn off the plymouth output of '5 dots' by removing 'splash' from the lines starting with 'linux' in .../boot/grub/grub.cfg.

Mount the usbboot partition, edit the file with nano and save it. Replace x by the actual drive letter for the persistent live drive, for example b or c.

sudo mount /dev/sdx3 /mnt
sudo nano /mnt/boot/grub/grub.cfg

Also, it seems that running command sudo update-initramfs -c
Gives me this output:

update-initramfs is disabled since running on read-only media

The strange output appears mentioning that I'm running on a read-only media. But the changes I make to the system are persistent. This is kind of confusing

'update-initramfs' is intended for installed systems, not for live or persistent live systems.

(The output message is somewhat misleading.)

[boqsc]

I think it is a compatibility problem between the graphics driver and and the graphics chip/card at an early stage of the boot process. One way to 'get rid of it' should be to turn off the plymouth output of '5 dots' by removing 'splash' from the lines starting with 'linux' in .../boot/grub/grub.cfg.

Mount the usbboot partition, edit the file with nano and save it. Replace x by the actual drive letter for the persistent live drive, for example b or c.

sudo mount /dev/sdx3 /mnt
sudo nano /mnt/boot/grub/grub.cfg

Well, this solution solves splash screen background problem by removing the splash screen itself.
No Splash screen - no Splash screen background problem.

[sudodus]

Well, this solution solves splash screen background problem by removing the splash screen itself.
No Splash screen - no Splash screen background problem.

That's right.

A problem with live and persistent live systems is that you cannot use a separately installed graphics driver (the overlay of a persistent live system is applied after the driver is activated). It might help with some boot option, for example 'nomodeset', but you might as well turn off the splash screen, so that is what I would recommend.

[boqsc]

Is there any known method to reconnect live persistent usb drive after it was accidently disconnected?

[sudodus]

Is there any known method to reconnect live persistent usb drive after it was accidently disconnected?

No, I am sorry, but I don't think so.

---

If you are lucky, there was nothing in the buffer (waiting to be written to the casper-rw partition), otherwise the data for persistence might be corrupted and you need to restore the casper-rw partition from the backup.

If there is no backup, you should wipe the content of the casper-rw partition and start from the beginning to install programs etc. It might be possible to save the content of your home directory.

[kurt18947]

@marks2,

Instead of fighting with a persistent live system, you can try to create an installed system in a fast USB 3 pendrive or an SSD connected via USB 3 or eSATA. This way you will get a system, where is it possible (maybe even easy) to install the Intel microcode, that you want. I am running such systems successfully, and I find them stable.

See this link with details to help with the installation: How do I install Ubuntu to a USB key? - install like into an internal drive

I've done this as well, installed to a generic USB3 flash drive. It seems to work fine though it's slower than installing to a HDD or SDD. My machine having USB2 ports didn't help anything, I'm sure. I can't comment about durability, i haven't used it that much. it used to be recommended to use an ext2 file system to reduce writes (no journal) but I've also read that the latest iterations of of ext4 don't produce much more flash wear than ext2. Just take your time and put the bootloader on the correct drive.

[boqsc]

@sudodus, Ubuntu 18.10 has been released, mkusb works fine, I'm writing from persistent Ubuntu.
Side note:
I've got an error printed out in the terminal while using mkusb:

- sed:tweak 3 grub.cfg
Failed Check carefully what happened

But as I said, it had no effect, at least so far, on operating system's usability.

[sudodus]

@boqsc ,

The error output you refer to is caused by the following code in the file dus-persistent of mkusb.

# tweak 3 grub.cfg

# search by UUID

partprobe
mount "$part" "$targ1" 2>&1
uid4="$(lsblk -Po name,uuid "${tu}4"|cut -d '"' -f 4)"
if [ "$uid4" != "" ]
then
 sed -i "s/set root=(hd0,4)/search --set=root --fs-uuid $uid4/" "$targ1"/boot/grub/grub.cfg
 if [ $? -ne 0 ]
 then
  error="$error - sed: tweak 3 grub.cfg"
  result="failed :-("
  echo "$result"
 fi
fi

It works for me, when run in an up to date installed Lubuntu 18.04 LTS (64-bit) to create Ubuntu 18.10. I used default settings (in mkusb).

The result in the file grub.cfg is

 menuentry "Run Ubuntu - persistent live" {
 search --set=root --fs-uuid 2018-10-17-22-44-30-00
        set gfxpayload=keep
        linux   ($root)/casper/vmlinuz  file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash persistent ---
        initrd  ($root)/casper/initrd
}

which means that the sed command was successful (and should return 0 on exit).

Please note that mkusb creates a persistent live system that works in most cases also when this sed command fails, but it will be more robust when the sed command succeeds.

---

Can you find something that is different in your case compared to my case? In what operating system did you install and run mkusb? Version and flavour of Ubuntu? Other possible differences? If you tell me the details I can create such a system and try to reproduce your result (with the error output).

[sudodus]

mkusb version 12.3.2 for version 19.04, Disco Dingo

The PPA at Launchpad includes versions of mkusb for the new developing version 19.04, Disco Dingo.

mkusb was tested today, 2018-11-05, with a Lubuntu daily iso file from the testing tracker, disco-desktop-amd64.iso, and it works as it should.

---

If you run standard Ubuntu, you need an extra instruction to get the repository Universe. (Kubuntu, Lubuntu ... Xubuntu have the repository Universe activated automatically.)

Text after the # character is not used by the shell interpreter, it is a comment for the human eye.

sudo add-apt-repository universe  # this line only for standard Ubuntu

sudo add-apt-repository ppa:mkusb/ppa          # stable PPA for regular usage
# sudo add-apt-repository ppa:mkusb/unstable   # PPA for development and testing; remove the # in front of the command to use it
sudo apt-get update
sudo apt-get install mkusb mkusb-nox

sudo apt-get install usb-pack-efi  # for persistent live drives that work in UEFI and BIOS mode with 32-bit iso files