Running Ubuntu off an SDCard on the new ARM Chromebook | Hacker News Reader

Running Ubuntu off an SDCard on the new ARM Chromebook

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114 pointsgeorgemcbay22 comments

Developer mode confirmed for the new ARM Chromebooks and Olof Johansson@Google has preliminary instructions for running Ubuntu off an SDCard.

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FWIW, if you ever order this or anything from Google Play online, double check all your order info. I ordered one of these this afternoon without realizing that the "ship to" address on my Google Play account was out of date (the billing address was updated, and that's all I noticed when I scanned the invoice).

Once you put in the order you can forget about getting any useful support when you notice a mistake like this. All I've been able to get out of their support is the same automated email sent to me about 10 times in response to my various queries. They are simultaneously (on different pages) telling me it is too late to cancel the order and yet the order won't ship until the 24th...

For a company that basically lives and breathes the web, Google ought to be totally ashamed at how god awful their online order support is. I've dealt with dozens of mom and pop online shops that run circles around this bullshit.

In the future I'll be sure to just be patient and wait for Amazon or someone else I can trust to get online retail right to have the item in stock.

Running an OS install off an SDCard isn't ideal, but perhaps most importantly developer mode is confirmed. It should just be a matter of time until it is trivial to reimage the internal ssd and u-boot directly into Ubuntu (or other distros with ARM builds) off the ssd. That plus a fast SDCard for data storage makes a very compelling Linux ultrabook-ish-system.

I dual boot my CR48 with Ubuntu. It also has a 16did SSD, so space is tight. I do use an SD card for extra storage, bu some applications (like Dropbox) don't like to use an SD card.

However this is basically a 2 year old prototype and it still serves me very well.

Here, here. I still use mine daily, even after getting an iPad.

> some applications (like Dropbox) don't like to use an SD card.

I'm probably just being dense, but why would an application want to know anything at all about the hardware underlying a directory? (It could probably parse /etc/mtab and make an educated guess, but why go to the trouble in the first place?)

I don't think the parent was suggesting that Dropbox was specifically saying "this is an SD card, I will die now."

More likely, it's pattern of fs access aren't ideal for an SD card.

> More likely, it's pattern of fs access aren't ideal for an SD card.

Well, this makes sense.

I imagine reimaging the built-in SSD should be relatively simple. It may be a little more complicated to turn off the signed boot validation and the developer mode warning.

The ability to reimage the SSD is the last hurdle preventing me buying one.

I assume this will happen relatively quickly. I'll pick one up as soon as they are available to the public; using ChromeOS in the meantime can't be all that bad.

I really like the idea of booting a system off an SD card or thumb drive, just seems really cool. That said, it seems like it would be really slow, unless you managed to somehow run entirely in RAM (optionally writing to disk at some point, or not if you were doing exclusively cloud / remote stuff).

I only looked into it briefly but it seemed complicated for me to set that up. Bonus points, new macs use EFI rather than standard BIOS, which seemed to make things even more confusing.

I'm running Ubuntu on my chromebook with an SD card (the only easy way to dual boot) and it's not slow at all. Maybe it's because it's the Sandisk Ultra-speed card, but I benchmarked it and it's actually faster than my old netbook's SSD.

So this seemed insane to me. SSD stalking has become a bit of an obsession of mine, and the thought that an SD card could beat out an HDD was hard enough; that it could beat out an SSD bordered on blasphemy.

But it has proved to be plausible. A gloss for those in the same boat as I was:

I just did a "hdparm -tT /dev/sda" on my bluelight-special 5400 rpm laptop drive and it is getting 3,100 MB/sec cached reads. The absolute fastest reads I see reported with the Sandisk Ultra cards on Amazon is 45 MB/s, with a few 30 MB/s reads, and mostly 20 MB/s reads.

Something doesn't add up here.

But the thing that really matters for bootup time, application load time, and application responsiveness time is 4k random reads. And 4k random reads for my bluelight-special 5400 rpm drive are:

4K random reads: 494 KB/s (KB!!!)[0]

According to the number one google result for "4k random read sandisk ultra"[1]:

4k random speeds: 4,499 KB/s

There are definitely some older SSDs that come in at around 2,350 KB/s (6,000 iops) for their 4k random reads.

So moral of the story: just buy a new SSD already with 4k random reads of 250,000+ KB/s.

[0] Using iozone. command:

  iozone -e -I -a -s 50M -r 4k -i 0 -i 1 -i 2

[1] http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=4...

Thanks for the data. Gotta love people who test their hypothesis and share it with HN!

Your harddrive is doing 3,100 MB/s? That's just over 3 GB/s, which I really have a hard time believing. Or is that a European comma, i.e. it's really doing 3.1 MB/s? Quite confusing. :/

Nope, American comma. Now that you mention it, it seems high to me as well. I just figured out why:

That is cached or buffered reads.[0] The buffer appears to be a small amount of memory that sits on the HDD. In addition to housekeeping, it seems mostly useful for read-ahead, which seems like it helps a little bit when you are accessing the same part of the HDD repeatedly (i.e., usually). On my HDD it is 8 GB.

RAM is faster than cache though. My RAM has a peak transfer rate of 10666 MB/s (DDR3 1333). Stuff sits around in your RAM after being loaded until something else needs the space. So buffers help with initial loads from the HDD. But after that, RAM is king.

For sequential reads/writes to my actual disk, the speeds are 15,000 KB/s to 50,000 KB/s (faster for larger files).

So yeah. SSD still the way to go for any form-factor that can handle it. But it's nice to know that SD cards have gotten to the point where they rival and sometimes beat HDDs in terms of real-world performance. The range of possible applications for the Pi and its ilk just expanded in my mind.

Yay, learning!

[0]http://en.wikipedia.org/wiki/Disk_buffer

I run ubuntu 10.04nbr on my eeepc off of an sd card. It varies between truly awful and not that bad, depending on the particular card I'm using. None of them are top of the line cards, mostly Transcend SDHCs of various capacities. The 8 gb one works well, one of the 16s is ok, the other is crap. The higher speed, larger cards are optimized for throughput, not random writes.

In the ok range, I could get work done-- chrome, emacs, and a web stack running. Page loads revere slow, but usable. I don't think I'd set a machine up this way again, it's just too much of a pain for what I'm getting out of it.

I've worked a lot from Live Linux USB sticks and the speed is not problematic. Typically in a Live environment everything is stored sequentially and on a compressed filesystem, which also helps. I've also run Linux completely from ram quite a few times which is really fast after the initial slow loading process (copying everything to ram takes awhile).

If you're worried about speed you could try to find a small SSD (and/or look for USB3, there are some cheapo usb3 drives out there. I don't know if the flash storage is fast enough to matter though.)

To get it to boot, all you really need to do is make sure that you use GRUB2 and do an EFI install to the external SSD. (Ubuntu will do this automatically, as will Fedora and no doubt others). (I want to say that rEFIt would handle this no matter what, but I can't remember even with my own MBA when USB will work with the EFI->BIOS bridge.

Having been a PPC linux user in the past, I'm a little wary of jumping into ARM. The 3rd party stuff, particularly Flash, not being there or being kind of crummy was a thumb in the eye of an otherwise great system.

Your number one concern is not having Flash?

I've ordered one of these, along with a 64GB high speed SD card, will definitely be giving this a try.

The only shame is that the Chromebook doesn't seem to come with a UHS-1 [1] interface, just SDHC/SDXC

http://www.integralmemory.com/faq/what-uhs-1

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