Who's is going run the OS from the SD card?


Austin25

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I heard (thought) that there would be fewer problems with running the OS from an SD card because then it sets the SD card as the root rather than the NAND. Anyone doing this or going to do this?
 
Doing (even at the moment). Very good for development / other hacking stuff :)


My NAND linux is a stock HF4 for PND testing and for recovery from bad autoboot.txt edits or the like.
 
I'm going to do this. I'm a big fan of repos and I want to use them without worrying what it's going to do to the NAND. Plus I'm paranoid about read/write cycles. Also there's an element of me just doing it because I can.
 
Can anyone explain the advantages of doing this?


And if there are some maybe link to a how to guide.


Ta
 
known advantages include not bricking your pandora in any way, and running off sd is much safer for experimenting as sd cards are easily replaceable, NAND inside the pandora is not, thought the lifespan of nand should be more than enough for anything a normal person can throw at it, for maybe 15 years if im not mistaken, so if youre still using 15 year old computers on a daily basis, running OS off sd is something you should ocnsider
 
mm i wonder if the ssd in my eeepc 701 (4go) is some kind of nand.. it's been couple years it's running 24/24 and the ssd doesn't show signs of failure yet..


i don't know, perhaps we don't have worry too much about this read/write limited cycle ..


Mac
 
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I too am attracted to this, but not because I want to save the NAND - it's because the Pandora's disk activity LED doesn't trigger on reads/writes to NAND, and it looks like the machine has locked up when extensive access is being made. If I boot from the SD, I'll get blinkenlights properly.


As an aside, why doesn't NAND access trigger an LED?


D.
 
mm i wonder if the ssd in my eeepc 701 (4go) is some kind of nand.. it's been couple years it's running 24/24 and the ssd doesn't show signs of failure yet..


i don't know, perhaps we don't have worry too much about this read/write limited cycle ..


Mac

yes an ssd is similar to nand flash, and has a limited number of write cycles, due to wear levelling and other shiny things like that they'll last a damn long time though
 
I will be doing this as well. I plan to experiment with different OS configurations anyway, so I'll reserve one SD slot for OS and the other for data.


The NAND will be my backup in case I screw up :)
 
There's few Arch Linux ARM projects going on, which I'm interested into. Whenever they get first release out, my SD card belongs to that.
 
mm i wonder if the ssd in my eeepc 701 (4go) is some kind of nand.. it's been couple years it's running 24/24 and the ssd doesn't show signs of failure yet..


i don't know, perhaps we don't have worry too much about this read/write limited cycle ..


Mac
I think there was some research that even cheap flash can handle hundreds of thousands of write cycles, so with good wear levelling (which afaik works below the block level, transparent to any filesystem or OS) even a very cheap flash device should last years, even if you're writing to it constantly at full transfer rate.


I thought you would be able to recover from it even once it stopped taking writes, but I don't know. A lot of flash-specific things happen below the filesystem level (which is often just FAT or something >_>), so it might not. If you can, that would be really cool, and a huge advantage over hard drives, which, from what I've heard, usually destroy themselves once they start to fail.

There's few Arch Linux ARM projects going on, which I'm interested into. Whenever they get first release out, my SD card belongs to that.
Hell yeah. Let me know if that works, like for wi-fi and GPU / DSP drivers and the standby switch.
 
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We've got two SD slots, haven't we? One for an OS and one for interchangable media. IMO it's insane to NOT run from SD. That way you can embark upon as much linux hackery as you desire without worrying about the root filesystem either becoming corrupted, or simply not fitting into the space available for it.


After the space problems I had with the N810, and the N900, I'm not touching a NAND-based rootFS ever again, if I can possibly help it. What can I say? I like in-development stuff, and wanton hackery.


Also, you can back up your SD-based root filesystem, simply by shoving it into a computer and creating a disk image of it. So if you *do* screw up, you can restore.
 
...


Also, you can back up your SD-based root filesystem, simply by shoving it into a computer and creating a disk image of it. So if you *do* screw up, you can restore.


...

Interesting, I've been wondering about that and thinking how great it would be if someone were to create a range of images that could be shared via torrents.


Perhaps one with a minimum install, another with all sorts of applications, games & emulators pre installed, maybe one with debian etc.


This would be a great addition to the Pandora scene IMHO.
 
Running from SD card should also making installing applications from the normal repositories a lot easier as you don't have the strict size limitation of the NAND and all dependencies are actually stored on the card itself making it impossible to eject your dependencies.


You wouldn't even need the PND system with this approach as you can easily fit all emulators and games on the OS card and just place the roms on the data card. Nevertheless, having portable games and applications (PND) is a nice feature.
 
You can't brick your pandora; even if you wipe NAND, you can still boot from SD.


There is no problem booting and running from NAND; booting from SD or NAND is up to you, and they present different things; the main thing is of course booting from SD gets you much more space, which can be very handy. It can be faster or slower, depending on your SD. You also don't 'use up' your NAND write-count, but thats not something many have to ever worry about anyway.


So boot from SD for the right reasons (because you just want to, or for more space which is great for dev, or to have multiple different firmwares, etc), but do not feel you _have to_.


jeff
 
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