UBIFS / Installer

[NewIT_Marcus]

Today we have added to the shop a number of pre-configured SheevaPlugs with the UBIFS file system.

You may perform the configuration yourself by following the instructions at the plugcomputer.org forum; the relevant pages are here and here.

This is an alternate configuration that improves upon the base configuration. It is still an Ubuntu 9.04 system, although the preinstalled package list is slightly different.

The advantages are:

* Quicker boot time (30 seconds instead of 2 minutes).
* Quicker file access times.
* The configuration steps that are necessary on the "base" offering are not required.
* The kernel version of the UBIFS configuration is 2.6.30.2

See also:

• http://plugcomputer.org/plugwiki/index.php/New_Plugger_How_To#Pause_for_a_second
• http://plugcomputer.org/plugwiki/index.php/Enabling_UBIFS
• http://plugcomputer.org/plugwiki/index.php/SheevaPlug_Installer
• http://plugcomputer.org/plugforum/index.php?topic=717.0

Modified to fix link.

[akc42]

You may perform the configuration yourself by following the instructions at the plugcomputer.org forum; the relevant pages are here and here.

First off, I think your first "here" has the wrong url (installer twice inside the [url= ...] ).

I just wanted to ask a few questions on this in relation to what I am trying to do.

I have just successfully installed Debian (Squeeze) into an SD card, and loaded it up with all the applications I think I am going to want in the final configuration.  This gives me a total usage of 860M, or which 363M is in /var. (so 497M is elsewhere).

My planned usage of this box is to be the home gateway router to my broadband ISP, using iptables as the firewall.  It will also support DHCP and DNS serving within the home (using dnsmasq) and key sets of web sites that I broadcast to the outside world, (using wordpress, mysql and postgresql).

It seems to me, that I ought to downgrade to debian stable (my current full PC with these web applications uses debian stable - but it also does a lot more), but more importantly, I would like to separate the essentially read-only (for the majority of the time) part and put it on the flash, and reserve the sd card for swap, /home and /var (probably using LVM so that I can dynamically change the allocations).  Provided it is properly backed up, I can then change the sd card if it ever gets worn out from writing.

As you can see, 497M is pretty close to the 512M limit - and although I have probably put most things I need in to the mix, if I have forgotten something or security updates or whatever increase that, I could be in difficulty (a way out is to take a subdirectory and move it to the sd card with an lvm logical partition).

So my questions.

1) Does ubifs compress stuff much such that I would probably get more that the 512M limit.
2) Why have you linked to the SheevaPlug_Installer - is that a way to get the most up to date linux kernel 2.6.30.2?
3) The instructions seem to imply you already have a rootfs - but I don't quite understand where you get the rootfs from.  If I just make a copy of the  existing rootfs - ie sd card contents (minus the home and var directories - ie that which I need read only) -  to a directory in my home I won't have the correct uImage and or uInitrd.

[NewIT_Marcus]

You may perform the configuration yourself by following the instructions at the plugcomputer.org forum; the relevant pages are here and here.

First off, I think your first "here" has the wrong url (installer twice inside the [url= ...] ).

Thank you; fixed.

So my questions.

1) Does ubifs compress stuff much such that I would probably get more that the 512M limit.
2) Why have you linked to the SheevaPlug_Installer - is that a way to get the most up to date linux kernel 2.6.30.2?
3) The instructions seem to imply you already have a rootfs - but I don't quite understand where you get the rootfs from.  If I just make a copy of the  existing rootfs - ie sd card contents (minus the home and var directories - ie that which I need read only) -  to a directory in my home I won't have the correct uImage and or uInitrd.

These questions are probably best answered out of sequence, and with a preface:

Preface: We are offering a UBIFS configuration in our shop and this page is intended to provide a bit of background. It has some relevance to other projects, but is not designed to solve or tackle problems, except to explain why we are offering this configuration.

So...

2). We linked to the installer, because that is the method by which we create this configuration. The installer can be used for other things besides.

1). The reasons given for using UBIFS here say nothing about the compressibility of data under UBIFS. I can't say if it is a significant factor either way, although (as it happens) the rootfs that is used is somewhat smaller than the factory configuration, so there is more space available - but this is due to a leaner set of packages, not the file system itself.

The installer is one way to get a more recent kernel, but not the only way. Again, see plugcomputer.org

3). What procedure are you using when trying to install debian? There are downloadable rootfs's. See the plugcomputer forum for discussion, and cyrius.com for specific instructions and links to downloadable lenny rootfs: http://www.cyrius.com/debian/kirkwood/sheevaplug/

Since you have your roots on a card, I would expect you to be around 1/2 way down this page, so your next step would be working on U-Boot.


Unfortunately, I still haven't had the time to install debian. When I do, I'll try to post some clear instructions. I don't know if this helps.

[akc42]

So my questions.

1) Does ubifs compress stuff much such that I would probably get more that the 512M limit.
2) Why have you linked to the SheevaPlug_Installer - is that a way to get the most up to date linux kernel 2.6.30.2?
3) The instructions seem to imply you already have a rootfs - but I don't quite understand where you get the rootfs from.  If I just make a copy of the  existing rootfs - ie sd card contents (minus the home and var directories - ie that which I need read only) -  to a directory in my home I won't have the correct uImage and or uInitrd.

These questions are probably best answered out of sequence, and with a preface:

Preface: We are offering a UBIFS configuration in our shop and this page is intended to provide a bit of background. It has some relevance to other projects, but is not designed to solve or tackle problems, except to explain why we are offering this configuration.

Understood, and I was nervous about asking the question here - but I administer an SMF forum elsewhere, and I know you can split the thread and move it if not in the right place - so I went ahead anyway.  I have read all of the plugcomputer.org stuff, but wanted to understand the whole process from beginning to end before I take a not quite but almost irrevocable step

So...

2). We linked to the installer, because that is the method by which we create this configuration. The installer can be used for other things besides.

1). The reasons given for using UBIFS here say nothing about the compressibility of data under UBIFS. I can't say if it is a significant factor either way, although (as it happens) the rootfs that is used is somewhat smaller than the factory configuration, so there is more space available - but this is due to a leaner set of packages, not the file system itself.

OK - just have to experiment then.

The installer is one way to get a more recent kernel, but not the only way. Again, see plugcomputer.org

3). What procedure are you using when trying to install debian? There are downloadable rootfs's. See the plugcomputer forum for discussion, and cyrius.com for specific instructions and links to downloadable lenny rootfs: http://www.cyrius.com/debian/kirkwood/sheevaplug/

Since you have your roots on a card, I would expect you to be around 1/2 way down this page, so your next step would be working on U-Boot.


Unfortunately, I still haven't had the time to install debian. When I do, I'll try to post some clear instructions. I don't know if this helps.

I DO have Debian installed and working, booting from the SD card.  Its the "Testing" version, but I also feel competent to get Lenny working (even through the process is different).  I was not asking how you installed Debian - I know you install Ubuntu.  I was asking where the rootfs comes from - but having how looked in detail at the sheeva installer, I now understand. 

I was also making a wrong assumption, thinking that the uImage and uInitrd files were loaded into the NAND prior to booting, but I now realise that the environment variables are in NAND and that the files are loaded into RAM (although I haven't figured out where yet) from the rootfs as booting takes place.

Thanks for taking the time to answer - I'll go pester the forums on plugcomputer.org for a while.

[pts]

A Bering ucLibc  firewall may work http://leaf.sf.net it's based on uclibc and runs in memory.
I'm not sure of status on running on Sheevaplug