Author Topic: Loosing which data?  (Read 3081 times)

Anonymous

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Loosing which data?
« on: January 16, 2004, 01:47:51 pm »
Hi there!

I\'m a freshly baked owner of a SL5500, and I\'m soon gonna start to customize my ROM and stuff... but I have some questions first. They\'re probably answered somewhere, but I wouldn\'t have found out, so any pointers to documentation is welcome. I use some OpenZaurus ROM, but I don\'t know which (I bought a used Z, and don\'t know which one is installed; not the latest one, I guess).

Now, all my questions are about that RAM/ROM thing, and I could just ask \"Which data is lost when?\". But to be more specific: One has 3 areas of memory: The ROM, a part of the RAM, where data is saved (call it the Ramdisk), and the RAM itself. I think, whatever power you loose for how much time, the ROM stays as it is, right? And if you do a reboot, the RAM is lost, yes? But what about the Ramdisk? What if I reboot? What if I run out of battery power/replace the battery? I read about an additional battery that\'s supposed to keep the RAM alive, which runs about 24 hours, does that apply to the ramdisk?

Secondly, how can I use what memory? Ok, I can\'t directly use RAM, but what about the other 2? I want to have some files from my desktop on my Z, where should I put them? When I use \"mount\" I find 2 mounted ramfs\'s, does that mean that there are actually 2 ramdisks? One is mounted on /dev, the other one on /var, which doesn\'t actually make to much sense for me...

Hmm, so far  If anybody can answer any of these questions, I\'d be grateful. I read the docs on openzaurus.org, but I didn\'t really get it...

Cheers
Philipp

lardman

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Loosing which data?
« Reply #1 on: January 16, 2004, 08:08:29 pm »
Quote
Now, all my questions are about that RAM/ROM thing, and I could just ask \"Which data is lost when?\". But to be more specific: One has 3 areas of memory: The ROM, a part of the RAM, where data is saved (call it the Ramdisk), and the RAM itself. I think, whatever power you loose for how much time, the ROM stays as it is, right? And if you do a reboot, the RAM is lost, yes? But what about the Ramdisk? What if I reboot? What if I run out of battery power/replace the battery? I read about an additional battery that\'s supposed to keep the RAM alive, which runs about 24 hours, does that apply to the ramdisk? 


Don\'t quote me but....

With OZ the ROM is never lost (until you reflash or delete things yourself)
The RAM-disk is not lost between reboots (so I\'ve heard)
The RAM (as in program memory) is lost.

Personally I run a 64-0 ROM so I don\'t have a RAM-disk to worry about.

Quote
What if I run out of battery power/replace the battery? I read about an additional battery that\'s supposed to keep the RAM alive, which runs about 24 hours, does that apply to the ramdisk? 

RAM is RAM, it should keep both the RAM and RAM-disk alive.

/root (also known as /home/root) is on the flash ROM, I\'m not too sure about where the mount point for the RAM-disk is.


Si
C750 OZ3.5.4 (GPE, 2.6.x kernel)
SL5500 OZ3.5.4 (Opie)
Nokia 770
Serial GPS, WCF-12, Socket Ethernet & BT, Ratoc USB
WinXP, Mandriva

Anonymous

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Loosing which data?
« Reply #2 on: January 16, 2004, 10:00:22 pm »
Quote
The RAM-disk is not lost between reboots (so I\'ve heard) 

To be more specific, the RAM-disk is not lost during a soft-reboot.  It is lost during a hard reboot.  i.e., one where the power to the RAM chips get lost, like if you remove the battery or possibly a hard reset if there is such a thing.  It\'s the same way the the program memory works on Pocket PC devices.

Anonymous

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Loosing which data?
« Reply #3 on: January 17, 2004, 04:53:09 am »
Thanks for the answers

So, to get it clear, the really important stuff has to go to /root, because that\'s the only part that\'s never going away? If I use ipkg to install new progs, is that going to the ROM or the Ramdisk?

Yeah, maybe you have some link for me about that? I haven\'t found real documentation about almost all of the software, I mean, something like a manpage, where ALL details are explained or so... Anyway, I\'ll find out by try-and-error, so thanks for your help

Cheers
Philipp

lardman

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Loosing which data?
« Reply #4 on: January 17, 2004, 07:59:14 am »
Quote
So, to get it clear, the really important stuff has to go to /root, because that\'s the only part that\'s never going away? 

Yep. But as ever make backups.

Quote
If I use ipkg to install new progs, is that going to the ROM or the Ramdisk? 

Depends where you tell it to install. The choices are: root, ram, cf, sd.


Si
C750 OZ3.5.4 (GPE, 2.6.x kernel)
SL5500 OZ3.5.4 (Opie)
Nokia 770
Serial GPS, WCF-12, Socket Ethernet & BT, Ratoc USB
WinXP, Mandriva