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OESF Portables Forum > Everything Else > Archived Forums > Distros, Development, and Model Specific Forums > Model Specific Forums > Sharp Zaurus > C1000/3x00 General discussions
Can someone explain the difference between a NAND backup/restore from the Service menu and a backup/restore from the settings tab?
I'll explain Backup/Restore from the settings tab, as I haven't used NAND Backup/Restore.
I have only used this in Cacko.
This Backup/Restore option allows you to create images of settings & programs installed, in increments.
This Backup/Restore option allows you to restore your Zaurus to a previous state, within Cacko.
In other words, you must have a "Working" ROM (Sharp/Cacko)
I keep many backups using this method. I have about 22 of them archived to DVD.
Back when I first got my Zaurus, I once started over with Sharp rom.
Then I installed Cacko and didn't tweak or adjust anything.
Then I used Restore, and restored ONE of my Backups.
Now my Zaurus was in the same "state" as it was when I made THAT backup. smile.gif

BTW, you'll get more responses to this thread if you edit the title to something more descriptive...
NAND backup/restore...

It is not OS dependant... you don't have to have a running OS to do a restore or backup...

It his backups up EVERYTHING... full file system... from begining to end... even empty space...

Good for if you have a perfect running copy of any ROM...


PS HoloVector is repling as a type so his will prolly be me indepth... I dont have time now to "Break it down"
Nice Description Jon_J smile.gif

To add on to what Jon_J said a NAND backup is useful when your Zaurus OS is no longer working. They are larger in size compared to the regular backup. A NAND is around 128MB in size because it is a backup of the entire Zaurus flash area while the regular backup file only has settings, documents and added applications it's about 64MB in size. I prefer NANDs because I like restoring everything back to exactly the way it was but, getting to the Service Menu is a pain.
NAND is a type of Flash Memory
Developed by Toshiba a year after Intel's NOR flash, NAND flash functions like a disk rather than memory. Flash Translation Layer (FTL) software makes flash look like a disk drive to the operating system. Reads and writes are sector-sized blocks of 512 bytes; however, typically, a 2KB page of four blocks are read and written at one time. Before writing, cells are erased in blocks ranging from 16KB to 128KB. Less expensive than NOR, NAND flash can be rewritten up to a million times, and erasing and writing NAND is faster than NOR

When creating a back-up of a NAND it is archiving each inode, every superblock, from zero to the last. (In the case of our Z's a full 128MB of installed memory) You do not need to have an OS installed to perform a NAND backup. (the service menu is not an OS per-se -- as long as the service menu functions you can reflash a NAND image) ... **as a note there are also two service menus .. in case one gets corrupted. They are accessed by hitting [D]+[M]+power and [Fn]+[D]+[M]+[Power] ( D+M stands for Diagnostic Menu)

The back-up/restore function is found in Sharp based ROMS (Cacko/Sharp) under that name .. I think it is called something different in OZ. pdaXrom does not have a utility built-in. backup/restore is OS dependent in that You need to have already flashed an OS on your Z. It is creating a tarball (compressed image) of the files you have specified. ie: your /home directory, also user space, configs, and installed programs... it generally does not archive the kernel, all system files, etc ..

To restore from a restore/backup tarball you need to have a working OS flashed to your NAND memory. (generally the same version the tarball is originally from) the tarball then extracts your /home and configs so you can duplicate your settings.

A good way to think about it is that the NAND is the physcial base like your harddisc. a NAND backup archives everything where it phsycially is on the disc. the kernel, libraries, configs, etc... all remain exactly where they were when you created the image. You do not need to have an OS flashed to restore from a NAND image. it can be used to install a full system, OS, settings and all. for instance a C1000 owner running OZ could use a NAND backup from another user to install pdaXrom fully configured with extra prorgams already installed. it will overwrite EVERYTHING.

a backup/restore generally adds or alters whatever is already there. If you do not have a working image on the Z, the restore will fail. or if you try to use a backup/restore for a different OS then what you are currently running, the restore will fail.

hmmmm ... make more sense when to use which? I haven't needed to make a backup in a long time .. pdaXrom is very stable for me ... but I used backup/restore to keep my calendar data up to date, and avoid minor inconviences.
Hi all,

and the most important thing:
A NAND backup is just a large and dumb memory dump,
but the regular backup is a simple tar-file.
So it's easy to access files from a regular backup if
you just give it a .tar extension, you may even extract
files on a Windows box.


Marc Stephan
QUOTE(loji @ Oct 25 2006, 06:44 AM)
NAND flash can be rewritten up to a million times

I've already done one NAND restore so I've only 999,999 more to go - I'll have to watch that carefully then. tongue.gif

**as a note there are also two service menus .. in case one gets corrupted. They are accessed by hitting [D]+[M]+power and [Fn]+[D]+[M]+[Power]

Well I didn't know that! Could be useful.

Thanks to all who replied. I now know a bit more than I did about backups.
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