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Easy persistent storage for live-CD

July 15, 2019 — BarryK

Now that I am once again supporting a live-CD, have done some work on it to make it as easy as possible to use. By default it will bootup running totally in RAM.

I posted a few days ago how you will be able to override on the kernel boot commandline:

So you could specify a working-partition and folder, for example "wkg_dev=sdb1 wkg_dir=easyiso", however, that is awkward if you wanted to do it permanently, you would have to remaster the ISO file.

So, now have another method, super-simple. Just create a file named 'easyos-persistent-iso' in any partition with Linux filesystem (ext2, ext3, ext4, f2fs), in any folder, and the CD/DVD will find it and use it at next bootup. That is, that partition and folder will become the working-partition (variable WKG_DEV) and the path (WKG_DIR), so you will no longer running totally in RAM and will have persistence.

It's that simple, just create that file, then reboot the CD. One restriction is that the file can only be a maximum of two-deep, to minimise search time at bootup. So, if you have say sdc1 mounted at /mnt/sdc1, then you could create say /mnt/sdc1/easyos-persistent-iso, /mnt/sdc1/easyos-iso/easyos-persistent-iso, or /mnt/sdc1/frugal/easyos-iso/easyos-persistent-iso

Where "frugal" and "easyos-iso" are whatever folder names you want. A note about this naming: I recommend do not create a version-specific folder name such as "easyos-1.1", as Easy has powerful rollback and roll-forward capabilities, making such folder names unnecessary.

After bootup from the live-CD, if running in RAM there is now a warning message after the desktop has loaded. This was in Quirky, but not in Easy. The warning message warns about limited RAM space, and advises how to create the 'easyos-persistent-iso' file for persistent storage. 

I think that everyone will find this to be very simple and easy method to obtain persistence.  And, if you ever want to go back to booting totally in RAM, just rename that file, so it won't be found.  Or, if the persistent storage is on a USB-stick or SD-card, just unplug it before bootup. 

Tags: easy