[Q] File system and partitions - Galaxy S II Q&A, Help & Troubleshooting

Can some confirm if I understand correctly
As I understand internal GS2 memory is divided into several partitions:
/dev/block/mmcblk0p9 on /system type ext4
/dev/block/mmcblk0p7 on /cache type ext4
/dev/block/mmcblk0p1 on /efs type ext4
nil on /sys/kernel/debug type debugfs
/dev/block/mmcblk0p10 on /data type ext4
/dev/block/mmcblk0p4 on /mnt/.lfs type j4fs
/dev/block/vold/179:11 on /mnt/sdcard type vfat
So as I understand in CWM recovery:
format data formats dev/block/mmcblk0p10 on /data type ext4
format system formats /dev/block/mmcblk0p9 on /system type ext4
format cache formats /dev/block/mmcblk0p7 on /cache type ext4
wipe data / factory reset - on stock deletes everything from dir /data or just some files from dir /data
wipe cash - deletes all files from from /cache or just some files from dir /cache
wipe dalvik- deletes all files from from /data/dalvik-cache or just some files from dir /data/dalvik-cache
format /sdcard formats /dev/block/vold/179:11 on /mnt/sdcard type vfat ????
format /emmc formats what????
In what partition is bootloader?
In what partition is kernel?
In what partition is CWM recovery?
Where are located download mode (home+down+power) system/files?
From recent experience I understood that nandroid is not doing backup of all partitions. EFS partition is not backed up.
What else is not backed up and what partitions are backed up?
What partition is backed up in nandroid boot.img file?

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Don't mess with them until you really know what you are doing
if bootloader gets messed up then its a brick

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I really don't want to have problem and that's why I'm asking.
When you know simple basics it much safer to change ROM's

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Well, if you'd search before asking questions, you'd have the information already.
Basically:
Code:
0 '/tmp' 'ramdisk' '(null)' '(null)' 0
1 '/efs' 'ext4' '/dev/block/mmcblk0p1' '(null)' 0
2 '/boot' 'emmc' '/dev/block/mmcblk0p2' '(null)' 0
3 '/recovery' 'emmc' '/dev/block/mmcblk0p6' '(null)' 0
4 '/cache' 'ext4' '/dev/block/mmcblk0p7' '(null)' 0
5 '/system' 'ext4' '/dev/block/mmcblk0p9' '(null)' 0
6 '/data' 'ext4' '/dev/block/mmcblk0p10' '(null)' -16384
7 '/preload' 'ext4' '/dev/block/mmcblk0p12' '(null)' 0
' 0 '/sdcard' 'vfat' '/dev/block/mmcblk1p1' '/dev/block/mmcblk1
9 '/sdcard1' 'vfat' '/dev/block/mmcblk0p11' '(null)' 0
Bootloader is in p2 and p3.
Kernel is in p5.
Recovery is inside the kernel.
Download mode (home+down+power) system/files is in initramfs (also kernel, basically).
Boot.img file contains the kernel if I remember correctly.
If you're concerned about partitions, back them all up with dd. However, be careful goes without saying

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Sure I was looking, but short and simple answer couldn't find
Thanx
And additional questions:
So if /system (/dev/block/mmcblk0p9) is deleted, then phone still should be able to boot into download or recovery mode? (because Bootloader is in p2 and p3; Kernel is in p5.)
Can it be that in boot.img is packed p2, p3, p5 partitions?

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/system comes with the ROM, so yes - you can delete it and still have recovery.
Why don't you extract the boot.img and see what's in it?

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Sure I've tried to extract but..
In phone "Nandroid browser" can't open
In windows "unyaffs" says "broken image file"
In windows "DiskInternals Linux Reader" also not working

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If you search you will find the post that shows how to extract on SGS2 and tools required .
jje

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limmes said:
In what partition is bootloader?
In what partition is kernel?
In what partition is CWM recovery?boot.img file?
Click to expand...
Click to collapse
i always formats system and boot in cwm 4.x.x but since 5.x.x only system is present, meaning formating boot is good but is more dangerous for all users to access.
formating system solves many issues.