3

I heard that while installing via USB (or Live CD), all files are loaded into ramdisk? And as far as I know, ramdisk is just RAM that behave as HDD.

My RAM is 4GB and ubuntu installation media is just (more or less) 1 GB. So basically, if all the files are loaded to RAM, RAM still have 3 GB to be used as actual RAM. So, is it save (or possible) to unplug Installation media while installing?

5
  • 1
    Why would you want to? Apr 21, 2015 at 18:27
  • I wouldn't as you're essentially unplugging the installation media that Ubuntu is using if you're doing so.
    – Sonickyle
    Apr 21, 2015 at 18:38
  • @Zacharee1 Just curious ;)
    – Mas Bagol
    Apr 21, 2015 at 18:39
  • @Sonickyle27 That's the point. It's the media (or just a medium), so may be I can just unplug it. (I'm running installation using USB right now)
    – Mas Bagol
    Apr 21, 2015 at 18:41
  • Ubuntu loads from it when installing. Doing so would interrupt the installation.
    – Sonickyle
    Apr 21, 2015 at 18:43

2 Answers 2

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Not all of the information is loaded into RAM. If you pull the drive Ubuntu will stop working because the commands are still on the USB drive.

I just tested this out, and I am replying to this without my USB drive in the system and it is working fine while I am still in the Try Ubuntu.

On your USB drive, modify boot/grub/grub.cfg and add toram to the following so both the Try and Install will work without the USB drive in:

menuentry "Try Ubuntu without installing" {
    set gfxpayload=keep
    linux   /casper/vmlinuz.efi  file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash toram --
    initrd  /casper/initrd.lz
}
menuentry "Install Ubuntu" {
    set gfxpayload=keep
    linux   /casper/vmlinuz.efi  file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash toram --
    initrd  /casper/initrd.lz
}
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  • toram causes the bootloader to copy the entire contents of the USB to RAM so that the USB can be pulled.
    – Terrance
    Apr 21, 2015 at 23:10
  • How can I edit boot/grub/grub.cfg file if it read only mode? It is actually behave as CD right? Because it is from iso file.
    – Mas Bagol
    Apr 23, 2015 at 9:38
  • @BagolDaplun If you use the Startup Disk Creator app in Ubuntu, you use the ISO to create a bootable USB drive. Once that is created, the boot/grub/grub.conf file on the USB drive will not be read only and can be modified. Do not modify the boot/grub/grub.conf on your hard drive as that file is actually controlled by another file.
    – Terrance
    Apr 23, 2015 at 12:57
  • @BagolDaplun On the other hand, it is a long and lengthy process to create a custom ISO that goes on a CD of the installer, but that file will have to be modified before it is burned to the CD/DVD. Here are some instructions help.ubuntu.com/community/LiveCDCustomization
    – Terrance
    Apr 23, 2015 at 13:02
0

Don't do it. Even if everything gets copied to RAM (which is highly unlikely), There is always going to be a time when the installation reads from the media. I have observed my USB stick flashing during the installation, so even if it's not copying anything, it might be reading certain files (ones that don't get installed). If you want to install Ubuntu on two machines at almost the same time, burn another DVD or USB drive.

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