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Rooting Galaxy S2 - Dummies Guide

To root your Galaxy S2, carefully follow the instructions in Rooting Galaxy S2 - Dummies Guide and you will need to add Root Explorer file Manager mentioned in it. I would go for the earliest /efs file backup that you have as the later ones may be compromised.

This post makes more sense to me: http://forum.xda-developers.com/galaxy-s2/help/solved-stuck-flight-mode-efs-issue-t1261948 , although this one http://forum.xda-developers.com/galaxy-s2/help/efs-recovery-t1331701 solved the problem as well

My progress so far:
I successfully rooted the phone and I installed ES file explorer.
I found the efs folder. There, I have nv_data.bin and nv_data.bin.md5 files and their date is shown as 2 oct 015.
I don`t have in the efs folder the .nv_data.bak & nv_data.bak.md5

Ive mentioned in the post before what efs files I have.

Also, I have installed ADB following this guide http://www.howtogeek.com/125769/how-to-install-and-use-abd-the-android-debug-bridge-utility/ and I can see my device when I connect it.
I have 7zip on my PC if I need to explore the .tar

I am not too sure what to do next, I`m scared of ruining it completely. ADB is very unfamiliar to me. Could you please guide me through this process as well ? Thank you
 
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As you are now successfully rooted, perhaps it might be a good idea to post in the general rooting forum as I have no experience of using ADB and you may receive a better response and we can keep this thread for rooting. Good luck!

Got it, will post there. Hopefully another kind person as you will be around there too. Thank you so much for everything!
 
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Best practice when switching from one custom ROM to another, (especially if it is to the CM nightly ROMs), is to unroot using SuperSU settings and flash a stock Samsung firmware and doing a Factory Data Reset before moving on to your new ROM. This ensures that you have a correctly working phone with no detritus left over from the previous firmware.

I've been using CyanogenMod 12.1 official nightly build for two days and i have to say i'm surprised at how stable it is. @ironass, thanks.
 
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First of all, thanks so much for all the work you put into this!

Here's my version details:

PDA : I9100XWLSD
PHONE : I9100BOLP9
CSC : I9100DTMLSB
Build Info : Thu Jan 31 14:30:29 KST 2013

Previous Kernel version: 3.0.31-889555 dpi@DELL228 #3 SMP PREEMPT Thu Jan 31 14:48:54 KST 2013
Current Kernel version: 3.0.31-Siyah-s2-v6.0b5+ gm@ubuntu #177 SMP PREEMPT Mon Feb 18 16:38:28 PST 2013

And here's my problem (if it has been discussed before, please just direct me towards where to find the solution):

I followed your instructions in posts #1 and #2, and everything seems to have worked just fine, except that my microSD card is now not recognized anymore. As soon as the phone is turned on, it tells me that "the SD card may now be removed safely." When I go into the settings to "Connect SD-card" manually, it does so for a split second, before removing it again.

I'm thinking that the problem may be the card's size (64GB), as I remember the sales clerk telling me that this size hadn't been supported on the Samsung Galaxy S2 from the beginning, but that a later fix had been released for it to work. I ended up never having a problem with it until now, and an older 32GB card seems to get recognized. Unfortunately, tons of files I need to access, including apps, are saved on said 64GB card and I desperately need it to work on my rooted phone.

Is it the kernel that puts me in this predicament? The ROM? What options are there for me? Is there an easy fix, or any fix at all, for this problem?

Thank you for any help you can provide!
 
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First of all, thanks so much for all the work you put into this!

Here's my version details:

PDA : I9100XWLSD
PHONE : I9100BOLP9
CSC : I9100DTMLSB
Build Info : Thu Jan 31 14:30:29 KST 2013

Previous Kernel version: 3.0.31-889555 dpi@DELL228 #3 SMP PREEMPT Thu Jan 31 14:48:54 KST 2013
Current Kernel version: 3.0.31-Siyah-s2-v6.0b5+ gm@ubuntu #177 SMP PREEMPT Mon Feb 18 16:38:28 PST 2013

And here's my problem (if it has been discussed before, please just direct me towards where to find the solution):

I followed your instructions in posts #1 and #2, and everything seems to have worked just fine, except that my microSD card is now not recognized anymore. As soon as the phone is turned on, it tells me that "the SD card may now be removed safely." When I go into the settings to "Connect SD-card" manually, it does so for a split second, before removing it again.

I'm thinking that the problem may be the card's size (64GB), as I remember the sales clerk telling me that this size hadn't been supported on the Samsung Galaxy S2 from the beginning, but that a later fix had been released for it to work. I ended up never having a problem with it until now, and an older 32GB card seems to get recognized. Unfortunately, tons of files I need to access, including apps, are saved on said 64GB card and I desperately need it to work on my rooted phone.

Is it the kernel that puts me in this predicament? The ROM? What options are there for me? Is there an easy fix, or any fix at all, for this problem?

Thank you for any help you can provide!

Hello and welcome to Android Forums meditate :)

As per the previous 779 posts, this is not a problem with rooting but rather, either the SD card, (I had a Scandisk card do this to me once), or, if you are using a custom ROM, the ROM itself. The S2 is OK with 64GB cards.

Copy all your information from the SD card and format in the phone settings and see if the phone recognises it. If so, you can copy your data back. If not, there could be a problem with a custom ROM or with the card itself, perhaps try it in another phone and check.
 
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Hi ironass, thanks for getting back to me! :)

To clarify, the card worked fine on the phone before rooting, and is still being recognized on other phones. :(

But I'm glad that this seems to be a more isolated problem, and will try your suggestion soon (I'll have to find space first). Once everything is copied safely, how will I be able to format the SD card through my phone, especially as long as it isn't recognized for more than a second? Is there a way? If not, what's the next best way, and do I need to consider formatting options?
 
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Alrighty, I tried several different 64GB cards, and made sure to have formatted them accordingly (though not through the phone, as it still kicks 'em out as soon as it's booted)... but nothing has helped so far. 32GB cards are fine, 64GB cards don't work anymore since after rooting the phone. :(

Can the root have reset something to the settings before larger cards were OK to use on a Galaxy S2, maybe?

Has anyone else here experienced this? Is there anything that I can try for this rooted phone to accept a 64GB card again? Any helpful suggestions or walk-throughs are appreciated!
 
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Yes!!! Thank you, ironass! This one actually, and finally, did the trick! :D

To anyone who encounters this problem, download and install the MiniTool Partition Wizard! Then change your micro SD card partition to regular FAT32! Tried to wipe the card first, but that took forever and repeatedly turned my PC off before it was done. Just changing the partition type was enough, though. (And don't forget to hit "Apply" after changing it, for it to actually take effect!) ;):cool:
 
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Another satisfied customer! ;)

Right, back on topic, I flashed the latest Lollipop, Android 5.1.1, ROM from CyanogenMod, (see post #2 for links), at the weekend, to a friends SG2, (actually, my old SG2), and it went very smoothly by carefully following the dev's instructions for both the Nightly release and the Pico gapps package. She is very pleased. This is for competent users but is well worth the effort. Make a nandroid backup first... just in case! :)
 
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Hi! I apologize for my noob questions, I've never done anything like this for my galaxy phones. I have an old S2, and I want to give it to my father (his LG sucks). The phone is in great condition except for performance lag. That is why I'd like to flash a custom rom. So in order to do that, I must first root my phone. Is that correct?
 
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Hi! I apologize for my noob questions, I've never done anything like this for my galaxy phones. I have an old S2, and I want to give it to my father (his LG sucks). The phone is in great condition except for performance lag. That is why I'd like to flash a custom rom. So in order to do that, I must first root my phone. Is that correct?

Hello and welcome to Android Forums HollowDean :)

That is correct. You will need to root your phone to flash a custom ROM.
 
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Ty for fast reply. Is there a step by step guide for flashing roms as well? I found a rom that's suppose to be stable (what I want) on xda forums, but I have no idea what instructions mean. For instance, like this:
Coming from 4.1.x or 4.2.x or 4.3.x or another ROM to 4.4.x:
  • Flash a kitkat compatible recovery from here. A kernel is a recovery and a recovery is a kernel.
  • Reboot to recovery. Not to the system!
  • Full wipe: data, cache, dalvik cache.
  • Mount system and format system partition manually.
  • Flash the unofficial build.
  • Flash gapps from here. Please use the 'minimal' one since our system partition is not big enough to carry the 'full' one.
This is my biggest problem. I don't understand a thing :(:oops:
 
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Ty for fast reply. Is there a step by step guide for flashing roms as well? I found a rom that's suppose to be stable (what I want) on xda forums, but I have no idea what instructions mean. For instance, like this:

This is my biggest problem. I don't understand a thing :(:oops:

There is a KitKat compatible recovery included in the rooting process in posts #1 & #2. Although you do not mention which ROM those instructions belong to... it looks like a CyanogenMod type ROM that involves re-partitioning the system partitions. Something I would only usually recommend for advanced ROM flashers as it can brick your phone if you don't know what you are doing.

My advice, for what it's worth, leave that ROM alone until you do know what you are doing or can get yourself out of trouble.



ironass motto... "Flash in haste... repent at leisure!" ;)
 
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Hello admin. I have rooted my Galaxy S2 long back like a year ago and i dont remember the kernel which I had installed. I guess its Jeboo_Kernel_v1.2a+ . I would like to create a swap file and support it with the phone but this kernel is not supported . Can i know which kernel supports for my sgs2 and what can be the procedure after rooting the phone once and again changing the kernel. Thanks.
 
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Hello admin. I have rooted my Galaxy S2 long back like a year ago and i dont remember the kernel which I had installed. I guess its Jeboo_Kernel_v1.2a+ . I would like to create a swap file and support it with the phone but this kernel is not supported . Can i know which kernel supports for my sgs2 and what can be the procedure after rooting the phone once and again changing the kernel. Thanks.

Hello and welcome to Android Forums Anas Ahmed :)

For detailed instructions on rooting your Samsung Galaxy S2, see post #1, #2 and #3 of this guide. Good luck!
 
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Hello and welcome to Android Forums Anas Ahmed :)

For detailed instructions on rooting your Samsung Galaxy S2, see post #1, #2 and #3 of this guide. Good luck!
Thanks for the welcome admin. I guess you didnt read my ehole post. I have rooted my phone already and i want to change my kernel , a kernel which supports swap file for my phone so could you help me which kernel supports swap file and what is the procedure to change the kernel after rooting once. Thank you
 
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Thanks for the welcome admin. I guess you didnt read my ehole post. I have rooted my phone already and i want to change my kernel , a kernel which supports swap file for my phone so could you help me which kernel supports swap file and what is the procedure to change the kernel after rooting once. Thank you

This thread is all about rooting the Galaxy S2. You could post in the general rooting forum if you have a specific post rooting question such as yours. That way we can keep this thread for those who are rooting their phones.
 
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