I'm trying to install Ubuntu Server 12.04 from USB and I've been struggling with it for 3 days. I don't remember I had this hard time even when building my Hackintoshes.
So, now I'm at the point where I tried everything I found - Unetbootin, Startup disk creator, Live USB creator - nothing really works, as it doesn't detect the USB as a CD-ROM. I tried the switch cdrom-detect/try-usb=true to no avail. At least now I managed to get over this problem with the following method. I make the USB boot disk, I copy the *.iso to the USB too, I boot the installer and when I get the CD-ROM error, I ALT+F2 and do the following:
mkdir /usb mount -t vfat /dev/sdb1 /usb ls /usb (so I see the name of the ISO clearly) mount -t iso9660 -o loop /usb/whatever-the-iso-is-called.iso /cdrom ls /cdrom (so I see it has mounted the ISO right)
So mounting the ISO in a word. I select "Load configuration from CD-ROM" or something like that and I got rid of the CD-rom error. Everything's peachy until I get to the Configure APT screen, where it can't connect to the internet because I'm behind a firewall and it doesn't give me the choice to enter the proxy and it just quits to the installation choices screen. Now if I tell the installer to let me configure what software I want installed, it just tries to configure apt, it fails and it quits to the choices screen. Then I can continue the installation with install grub, it installs it and it works after restart.
BUT i have absolutely nothing installed, not even nano, my sources.list is empty with only the CD-ROM resources line. I don't know what to do... I need LAMP, SMB, SSL, CUPS installed - I don't want to do everything manually. Has anyone succeeded doing a start to finish installation using USB? If yes, how? BTW, everything works OK if you install from the CD (even if I plug the LAN cable out, it still configures apt and it still populates the sources.list). But I don't have a CD drive on the system I want to do the final install too and I don't want to buy any external CD drive just to get this done. All help welcome, I'm going crazy with this...