Notices

Is it possible to do a complete backup of the N900 which includes the OS, apps and everything else?

Something which can backup and restore the N900 to the exact condition of a fully working system so that you don't have to reflash and then re-add everything else you had previously?

I am not sure that I have seen an answer to this so thought that I would ask.

I'm not sure how this is exactly done but you can make an image of your root drive (you just have to mount the ubifs partition), then it can be reflashed onto the device.

Myself and a number of people have requested this before. But there is a general lack of interest in the matter. Only theories so far. nothing practical.

Review following recent thread:
http://talk.maemo.org/showthread.php?t=48347

Nothing practical??
How about dd, for fat and ext2/3 partitions?
Or tar, for everything?
And mkfs.jffs2?
Put everything together in a script, boot from mmc, and there you have your full backup imaging (flasheable) sollution.
I do not have a N900, but I do it routinely in my N810

Hello guys !

I add my self to the request of a full backup apps for our N900.

We have talked about this also on this thread:
http://talk.maemo.org/showthread.php?t=48347&page=2

Any of the Maemo Gurus here have a solution for this problem ?

Thanks for the reply.
SkyEagle

Ok slow down mate. Slow people here.

dd for copying. ok great.
tar is for compressing
dont get the third one?
How does one boot from MMC?

Can you share the script you use routinely?

Thanks.

ok guys, much of what is touted above is new to me. I'm a linux newbie with the N900 so has someone come up with a dummies app or script that will do a complete backup for us novices who aren't very confident with the terminology that gets used when discussing this sort of thing?

we really need something simple that is easy to run and use.

The information maacruz gave may not be helpful for the N900. On the n800/n810 many users booted off an SD card. Thus the SD card could contain a partition like this..

Say 16 GB SDHC. 3-4 GBs for the OS, applications, etc.. (ext2 typE). Then the rest FAT32 for regular file storage (media, etc..). It was then easy to do a full back-up since one would just have to tar the 3-4 GB partition. Or do what I did and connect the n800 to a computer and make an image out of that partition.

However, with the N900 its' harder (most of us aren't booting from an microSD card or the internal storage). To do a back-up you have to somehow clone the 256 MB that the OS runs off of, and the 2 GB /opt partition. However, there's no way to access them while the N900 is running (as far as I am aware)..

You could probably tar it while the N900 is running but that would be pretty slow of a back-up process.

Ah. Exaaactly. That is what I was saying in the other thread. I'm starting to like you.

I said, reading the files wouldn't be the major problem, since we have access to hte file system. it's restoring them while things are running. So we need some sort of extra "mode" like the one used to flash.

If only one of he devs would share with me, the tech limitations of reversing the operation of the Flasher 3.5

I would be very grateful.

I once did an "interesting" server HW upgrade basically I set up the base system on a new upgraded (but otherwise close enough, I'll come to that later) box while the old was still running, then booted the new system up with separate IP, copied *everything* with tar piped over ssh to the new box, shutdown the old and rebooted the new.

Worked perfectly and downtime was measured in minutes (production server... this was of course done on the weekend but anyway).


250MB root partition is mounted normally while device is running, same for /home (2G) (/opt is just a symlink), so everything but the kernel should be accessible while device is running.

I'm not sure if there is some funky initramfs somewhere but I don't think so, thus the following should work in theory:

The naive way is to just pipe tar over SSH:

from device as root:

tar -cf - / | ssh me@myserver 'cat >n900.tar'

or from remote is you have ssh-server on device:

ssh root@mydevice 'tar -cf - /' | cat >n900.tar

Restoring is done in reverse, pipe the cat to tar and use -x.

Probably should have some way to detect the python-optify funky mounts (/opt/pymaemo/usr/lib/python2.5 mounted to /usr/lib/python2.5) and ignore the targets in our tar command. Ignoring /media/mmc1 and /home/user/MyDocs (SD-card and internal flash) is a preference thing.


Add any other tar options if you feel like it.

http://www.lamolabs.org/blog/1766/pu...ssh-scp-rsync/ (Wasn't the link I was actually looking for with some cool SSH piping tricks but looked good on the surface)

rsync is in many ways better for transferring the files but since we need to preserve file permissions and owners you need to run it as root somehow, rdiff-backup works essentially like rsync for the transfer part but it makes incremental backups so you can keep multiple versions.

Anyways that should be a start for experimentation, I have other things to break my device with so good luck...

Remember: It's not a backup until you tested it can be restored. main caveat here would be the kernel version, if you device is flashed with different version than the modules in your backup there will be trouble.

Edit: Just to clarify to restore after reflash make sure you have flashed to same kernel version that you used to have, then install ssh and do the restore and then reboot while hoping for the best.