3

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

Oxeuro
  • 33
  • Never heard of Rufus having persistence out of the box. Persistence can be added thus: https://askubuntu.com/questions/1126145/can-i-convert-a-live-ubuntu-usb-to-one-with-persistent-memory/1126305#1126305 – C.S.Cameron Sep 01 '19 at 16:44

1 Answers1

2

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.

Akeo
  • 1,455
  • Thanks for adding the persistence feature to Rufus. It is much better than just adding a couple 4GB persistence files. First attempt makes UEFI only Persistent drive. How to make Persistent drive that boots both UEFI and BIOS? It is good to know persistent partitions is fixed in 19.10. – C.S.Cameron Sep 02 '19 at 15:39
  • I also do not see a toram boot option on the boot menu, (that the OP asked about). This is easy to do, (even manually), and seems to add speed. – C.S.Cameron Sep 02 '19 at 15:47
  • "How to make Persistent drive that boots both UEFI and BIOS?": There's nothing special to do. Rufus will edit both the BIOS (Isolinux) and UEFI (GRUB) config files, so, by default, the persistent drive will boot both UEFI and BIOS, as long as you use MBR for Partition scheme and BIOS and UEFI for Target system (which should be the defaults anyway). "I also do not see a toram boot option (...) This is easy to do": Do you have a link to a tutorial or guide for that? – Akeo Sep 02 '19 at 23:24
  • Yes, Thank you, got it working. Good job on 3.7, I was stuck on 3.1. To boot to RAM I just add the word "toram" to the menuentry in txt.cfg – C.S.Cameron Sep 02 '19 at 23:45
  • 1
    Okay, that's more or less what I gathered from looking around. I did test that adding toram to the kernel options would load Ubuntu to RAM, but this really has nothing to do with persistence, and since it's not always easy to detect Live vs Install media (plus users need to understand what this really does) I don't think I will propose the option in Rufus for now. Instead I'll let people add the option manually, since, again, it's unrelated to persistence. I may of course propose that option in the long run, when it becomes more commonplace and easy to detect in a generic manner. – Akeo Sep 02 '19 at 23:50
  • Just added a persistent partition and NTFS partition to a UNetbootin install of 19.10. Looks like persistent partitions are working with syslinux like pre-14.04 days again, I think Rufus is the first to offer persistent partitions in a Windows app. A toram boot may be easier on the drive on server type applications. – C.S.Cameron Sep 03 '19 at 22:35
  • Thanks for the update. The problem with toram is that it takes noticeably longer to get to the environment due to the initial copy operation, which may throw users off especially if they have slow media (or slow RAM). Instead, I expect that the majority of users want to get to a running Ubuntu environment as fast as possible after boot, even if operating that environment is going to bit slower than if it was RAM based. As such, I don't see proposing the toram option in Rufus as a priority. But I may add a cheat mode for it. – Akeo Sep 04 '19 at 09:56
  • Sudodus has given mkusb has a toram option that might be worth checking out. – C.S.Cameron Sep 04 '19 at 17:02