Brad Q
Posts: 102
Joined: Mon Aug 12, 2019 12:10 am

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Tue Apr 07, 2020 1:39 pm

"I want a full USB Boot and not hybrid solution. This is why I would like to see a USB Boot as soon as possible. It was mentioned when the RPi4 came out."

We all know you want it. I am just asking what the significant advantage of direct boot over hybrid boot you see?

Edit: The quote was from bonzadog. I was trying to get him to explain his quote.
Last edited by Brad Q on Tue Apr 07, 2020 11:54 pm, edited 1 time in total.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 26876
Joined: Sat Jul 30, 2011 7:41 pm

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Tue Apr 07, 2020 2:35 pm

Brad Q wrote:
Tue Apr 07, 2020 1:39 pm
"I want a full USB Boot and not hybrid solution. This is why I would like to see a USB Boot as soon as possible. It was mentioned when the RPi4 came out."

We all know you want it. I am just asking what the significant advantage of direct boot over hybrid boot you see?
The ONLY advantage is not having an SD card in the Pi. No speed advantage - in fact the opposite, it's slower to boot.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

LTolledo
Posts: 3814
Joined: Sat Mar 17, 2018 7:29 am
Location: Anime Heartland

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Tue Apr 07, 2020 10:21 pm

jamesh wrote:
Tue Apr 07, 2020 2:35 pm
....No speed advantage - in fact the opposite, it's slower to boot.
this is true... slower to boot up...takes a few seconds slower.
the only real advantage can be realized AFTER boot up (be it USB thumbdrives, USB attached SSDs, but not much to USB attached HDDs).

so for fast boot and fast response after boot.... a "hybrid boot" method may be the best option available.

again I see no real advantage using NVMe drives, as it will only perform as if its an ordinary SSD when connected to a NVMe to USB3.0 adapter
I did tried this (I have one with me), and realized it

well.....each one has their own preferences....
"Don't come to me with 'issues' for I don't know how to deal with those
Come to me with 'problems' and I'll help you find solutions"

Some people be like:
"Help me! Am drowning! But dont you dare touch me nor come near me!"

bogoid
Posts: 1
Joined: Sat May 02, 2020 9:57 pm

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Sat May 02, 2020 10:14 pm

The Pi 4Bs arrived yesterday. Since then I did a clean install of buster onto a 128GB SD, then cloned the /boot part of the SD to a 2nd SD, and the everything else stuff to a 1T WD Elements USB3 drive, on an Amazon 4 port powered USB3 hub.

After fiddling /boot/cmdline.txt and /etc/fstab, it all works.

There were some pickinesses. I assumed that I could use root=UUID=<your favorite UUID here> but it would not come up, so I unplugged extra stuff from the hub (so the WD would come up as /dev/sda) and tried it with root=/dev/sda2, which worked. Then it occurred to me that the exaples I saw used root=PARTUUID=<your favorinte partition UUID here>, so I tried that, and things then worked.

There were the usual pilot error problems like using the wrong UUID/PARTUUID everywhere, but once it was sorted out it was fine.

I use Pis for DHCP and DNS servers at the various home networks, using dnsmasq, and as tunnel endpoints for access to/from other nets.

The Pi 4B seems to have much higher water pressure than the 3B+ (?) I've been using, and the 4GB is a nice kick in the pants, too.

I greedily await the no-SD boot, but I'm not foot-tappingly impatient.

Is there a way to help with that project? Like many others, I seem to have some time on my hands these days. It may as well go to something that benefits the community.

Brad Q
Posts: 102
Joined: Mon Aug 12, 2019 12:10 am

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Sun May 03, 2020 1:11 am

You probably could have saved yourself a ton of work by just using the usb-boot.zip utility. It pretty much automates all the work you did. The utility is available here on the site. Just do a search for it. RonR does a great job of supporting it.

W. H. Heydt
Posts: 13047
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Sun May 03, 2020 2:29 am

bogoid wrote:
Sat May 02, 2020 10:14 pm
Is there a way to help with that project? Like many others, I seem to have some time on my hands these days. It may as well go to something that benefits the community.
There is some expectation that a beta release of the EEPROM firmware supporting MSD over USB booting will arrive fairly soon. That is, weeks rather than months. Once the beta version has been announced, running it and reporting back (both positive and negative) will aid it getting it into full release.

W. H. Heydt
Posts: 13047
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Sun May 03, 2020 2:32 am

Brad Q wrote:
Sun May 03, 2020 1:11 am
You probably could have saved yourself a ton of work by just using the usb-boot.zip utility. It pretty much automates all the work you did. The utility is available here on the site. Just do a search for it. RonR does a great job of supporting it.
Yes...that's a good way for those who want a canned solution. On the other had, doing the setup manually on your own isn't difficult and may give one a deeper understanding of how it is supposed to work. One thing I decided to do was to use a larger FAT partition (512MB) against any future changes there, for instance.

User avatar
HawaiianPi
Posts: 5957
Joined: Mon Apr 08, 2013 4:53 am
Location: Aloha, Oregon USA

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Sun May 03, 2020 10:06 am

LTolledo wrote:
Thu Mar 19, 2020 11:41 pm
with the rootfs residing on the drives, there are no real world advantage between NVMe drive in USB3.0 adapters vs. regular SSDs in USB3.0 adapters,
That's correct, and there are significant disadvantages with heat and power consumption (as the OP discovered).

Using an NVMe drive on a Pi is kind of ridiculous. The enclosures are expensive and the Pi4 doesn't support USB 3.1 Gen2. In fact, the Pi4's USB 3.0 is only 4Gbps (not 5Gbps), and that's only when no other USB activity is happening, since all four USB-A ports share that 4Gbps bandwidth.

SATA-III is 6Gbps, which is faster than USB 3.0's 5Gbps, which is faster than the Pi4's 4Gbps, so a SATA-III SSD with a USB 3.0 adapter or enclosure (or a USB 3.0 SSD) is all you need.

rpdom wrote:
Tue Apr 07, 2020 7:24 am
Interestingly, I watched an interview with Eben yesterday. He was asked if it is likely that a future Pi would have a SATA interface. Eben said no and said that the USB adaptors work well for SATA so there is no point in building it in to a Pi. However he went on to add that if they did put any mass storage interface on a hypothetical future Pi, it would likely be NVME.
There are SBCs now with NVMe support, but they also only have a single PCIe lane, so that's mostly wasted. I've seen people harping on the Pi4's single PCIe lane not being exposed, but it's still a relatively slow 4Gbps interface, so adding a 4-lane PCIe NVMe drive to that would hardly affect performance over USB 3.0 (you might gain a little in latency).

If a future Pi model has multiple PCIe lanes, then it will be useful (otherwise NVMe is still wasted on that future Pi).

NOTE
You could buy the Pi4 system in my linked picture (minus the Fan-SHIM, but including the official PSU) for around the same price as just the NVMe enclosure in the OP (based on the current $105.99 price of the StarTech NVMe enclosure in the link).

Raspberry Pi 4B 2GB = $35.00
Crucial MX500 250GB SSD = $49.99
Eluteng adapter cable = $7.99
Acrylic 2 layer case with fan = $3.99 ($2.99 if you don't mind dark gray acrylic)
Official Raspberry Pi USB-C PSU = $8.99
Total = $105.96

Although to be fair, that is quite an expensive enclosure, but even cheap ones are much more than SATA ones.
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?

andrum99
Posts: 1264
Joined: Fri Jul 20, 2012 2:41 pm

Re: Raspberry Pi 4 boot-over-USB with NVMe drive

Sun May 03, 2020 3:29 pm

HawaiianPi wrote:
Sun May 03, 2020 10:06 am
...

the Pi4's USB 3.0 is only 4Gbps (not 5Gbps)

...
It's both 4Gbps and 5Gbps. 4Gbps is the bandwidth available to do actual work, 5Gbps is the raw bitrate on the wire, including protocol overheads - see the Data encoding section at https://en.wikipedia.org/wiki/USB_3.0

Return to “General discussion”