Ubuntu – Need a live cd to boot to ram


I created a live cd using uck and want it to boot to ram by default. How can I do this? I know I can hit f6 while booting and insert toram=yes, but like I mentioned I want this to be setup by default. Thanks in advance. Also I am a rookie when it comes to setting up ubuntu so more detailed instructions are needed.

Best Answer

I've done this before, add the toram option to the grub/grub.cfg file, turning the

linux ... noeject noprompt --

boot line into

linux ... noeject noprompt toram --

  • If you've got the live iso on a usb drive with a FS that's writable it's a lot easier, just mount & edit the grub file.

  • If you're using a cd/dvd or just dd'ing the iso straight to a usb then you'll have to edit the iso file before writing it, changing the grub file first and then write to cd/usb. I once found a nice little gui program that could do that, could've been isomaster but not sure. Or extract files -> edit -> make new iso with anything like mkisofs, k3b, brasero, etc.

(FYI, I can't recommend dd'ing an iso to usb, less than optimal and shreds the usb's MBR/fat)

Using the toram option is different from the regular overlayfs (formerly aufs?) that all Ubuntu (all Debian too?) live iso's use. This option copies all the needed data from the cd/dvd/usb into ram, so you can remove or edit the cd/usb, and generally run with ram FS read/write speeds (+2GB/sec) instead of cd/usb speeds (1-10MB/sec). But the expense is using up about a GB of ram.