Author Topic: Openzaurus 3.5.3 With Unionfs Support  (Read 2729 times)

comcute

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Openzaurus 3.5.3 With Unionfs Support
« on: October 01, 2005, 11:04:34 am »
Hello.
I have made some modifications in OpenZaurus with unionfs as a default root filesystem.
mtdblock4 is mounted in rw mode, but in union it's in ro mode (you can change it by altering /media/realroot/sbin/init.unionroot, if you dont' t llike it)
mtdblock6 mounted as /media/ram is on higher level branch in unionfs, so everything you write to / is actually written to /media/ram/packages.

I did not include unionroot-utils, because I didn't like their behaviour, these need some improvements.

If you want to test modified unionroot-utils, then send me PS or e-mail.
If you have programs installed to CF or MMC/SD card, then currently you can use them by adding unionfs branch with command:
Code: [Select]
unionctl /. --add /media/cf/packagesor
Code: [Select]
unionctl /. --add /media/card/packagesand before unmounting:
Code: [Select]
unionctl /. --del /media/cf/packagesor
Code: [Select]
unionctl /. --del /media/card/packages
Why unionfs?
Because it's stackable, you can merge the contents of directories, so you don't have to hassle with these symlinks anymore.
One more thing: I can use unionfs to save internal flash from wear levelling (maybe I'm paranoid?)

zImage-collie-40-24-2.4.18-rmk7-pxa3-embedix-r22.bin
opie-image-collie.rootfs-2005-09-30.jffs2 (unionfs-1.0.11)
opie-image-collie.rootfs-2005-10-02.jffs2  (unionfs-1.0.14)
opie-image-collie.rootfs-minifo-2005-10-03.jffs2  (mini_fo-0.6.1)


EDIT: OK, I have tested it for couple of days for now and found it sometimes gives still Oopses  Here is a demostration:

 [ Invalid Attachment ]

I have tested unionfs-1.0.14 as well and that didn't work at all, because setattr,delete=first mount flags were removed in that version. After chmod or write or etc working process freezed completely.
So, i think my next try is minifo filesystem.
« Last Edit: October 03, 2005, 12:00:39 pm by comcute »
SL-5500 running OpenZaurus 3.5.3
SMC EZ Connect (SMC2642w) 802.1b CF card
Sandisk 1GB SD card

Mickeyl

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Openzaurus 3.5.3 With Unionfs Support
« Reply #1 on: October 01, 2005, 05:41:00 pm »
Very interesting. The OZ team is experimenting with unionfs since long but we found it too unstable (oopsing on a lot of operations) yet. Which version of unionfs are you using and what patches did you apply to it?
Cheers,

Michael 'Mickey' Lauer | Embedded Linux Freelancer | www.Vanille-Media.de
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comcute

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Openzaurus 3.5.3 With Unionfs Support
« Reply #2 on: October 02, 2005, 07:08:15 am »
It's currently unionfs-1.0.11 (vanilla) and yes it isn't really stable, but it works if you use the "correct" (read working) fs parameters or you get oops. For exaple:
If one of the branch is ro mode and you have set delete=all, then it oops;
If one of the branch is ro mode and you have set setattr=all, then it oops;
SL-5500 running OpenZaurus 3.5.3
SMC EZ Connect (SMC2642w) 802.1b CF card
Sandisk 1GB SD card