Does Ubuntu live persistent USB use Intel Optane?

Question

I have a laptop with 16GB of Intel Optane. I have a live USB with persistent storage that I just created using Rufus. When I choose the option "persistent live to ram" does the machine use Intel Optane to accelerate the USB. If it does how can I check that ? Thank you

Answer 1

Rufus developer here.

I guess, first of all, I should address the Rufus + persistence question.

Recent versions of Rufus (3.6 and later) have added persistence creation "out of the box". However, because of Ubuntu bug #1489855, which prevents all versions of Ubuntu before 19.10 from properly mounting a persistent partition residing on the same media as the one it booted from (nothing to do with Rufus), some aspects of setting up persistence, such as automatically adding persistent to the kernel options, have been held back until Rufus 3.7.

So one thing you need to make sure if you plan to use persistence with Ubuntu and Rufus, is makes sure you use Rufus 3.7 or later (you can find the latest release here) as well as an Ubuntu 19.10 image that was released after 2019.08.01 (since the underlying bug from the casper package was fixed in late July), such as the ones from http://cdimage.ubuntu.com/daily-live/current/.

Otherwise, if you use Rufus 3.6 or earlier, or Ubuntu 19.04 or earlier, persistence as set up with Rufus will simply not work out of the box (but you may still get it to work with Rufus 3.6, if you use Ubuntu 19.10, by manually adding persistent to your GRUB or Isolinux config files).

Now, to try to answer OP's main query, I believe that persistent live to ram means the live OS is running from RAM, with any change made by the user (downloaded or edited files, etc.) saved to the persistent partition, which in the case of Rufus will be the second partition on the USB drive.

Whether Intel Optane can actually be applied (somehow, from reading on the technology I have doubts about that) and/or is effectively used will depend entirely on the Linux kernel that Ubuntu uses. From reading this article my guess is that the kernel will simply see Optane hardware as a regular NVMe block device and not do anything special with it. But if it were, I would expect to see clear mention of Optane acceleration being carried during boot and reported when issuing the dmesg command.

Still, unless you are using a Live media to carry out I/O heavy operations, which most UNIX people would probably recommend against (much better to go through a full OS install on the fastes NVMe drive you can afford, and boot from that), I don't believe using Optane acceleration to read/write persistent data will make much difference.