E: failed to mount /efs

How to Fix E: failed to mount /efs (invalid argument) in All Samsung Galaxy Phones.

If you are a hard core Android user who loves flashing ROMs and tinkering with your device to limits, all this can be a fun experience, but as you probably already know it does not come without some possible risks if you are not careful. Having a bad EFS folder can be your worst nightmare yet which cost many Android users sleepless nights. Troubleshooting EFS related problems like E: failed to mount /efs could prove to be an uphill task, more so like reviving a hard bricked device. A damaged EFS folder will cause your device to lose any kind of mobile networking capabilities leaving you unable to receive any calls, messages or access the internet. In Samsung devices, the EFS partition also the EFS folder houses critical information about your device core networking data: IMEI, WIFI, Bluetooth, MAC’s, radio info and others.
Most devices with a bad EFS folder/EFS partition will show “Blank IMEI” “Null Null” “Not registered on network” and probably Unknown Baseband version as well. A device IMEI is the unique ID assigned to every GSM phone and which can be used to validate a phone to the cellular network among other purposes. Without the proper IMEI data information, your device network tasks will not function.

YOU MAY ALSO LIKE: Solve Null IMEI, Unknown baseband, Not registered on network after downgrading Samsung Galaxy Phones

How to Fix  E: failed to mount /efs (invalid argument) in All Samsung Galaxy Phones

I recently had a Galaxy S2 i9100 for repair with blank IMEI number and No baseband version and no network at all. With no previous backup of the EFS folder or a backup of the IMEI, I graced myself for the task ahead.
The most recommended programs; EFS Professional and EFS backup/restore tool could not repair the corrupt EFS partition or restore correct IMEI data successfully.
Strange enough, while trying to flash stock ROM in ODIN, the device got stuck at the Samsung boot logo and could not boot all the way up, kept restarting. Then, I encountered this error in stock recovery. E: failed to mount /efs (invalid argument) factory resetting and clearing cache did not help either to solve the boot loop problem.
I tried upgrading the device from Ginger bread to official Jellybean 4.1.2 ROM in hope that a complete wipe would enhance the chances of solving the infinite boot loop and also repair EFS folder data which would get the network working again. I tried different Odin flashable Jelly Bean ROMS but after Odin finished with no errors, the device still could not boot past the Samsung boot logo, kept restarting frequently. Soon, I realized that no ROM flash, kernels flash or CWM jigs could resolve the error. I had to repair the damaged EFS mount point first.
I scoured on the internet but information about fixing this error was scanty and I could not find a working solution to fix Galaxy S2 EFS failed to mount.
At last, I stumbled upon some information about ” failed to mount partition” errors for another device. So I did my diligent research on getting the same to work on my Galaxy S2 and possibly every other Samsung Galaxy device out there with E: failed to mount /efs problem.
So today am posting this solution in the hope to save many others the agony of getting stuck with a seemingly useless device.

NOTE:  This solution has worked on GS2 i9100, Galaxy Note 3, and Galaxy tab 3. If you are having the same problem with another Samsung Galaxy device, this same tutorial will could work but you MUST change the EFS mount point  I.e ‘mmcblk0p…’ part to match your specific phone or tablet EFS mount point number. For instant, Galaxy S2 i9100 EFS mount point is mmcblk0p1, for Galaxy S3 i9300 use mmcblk0p3 , Galaxy Note 3 use mmcblk0p3 as well and so on depending on your particular device partition table. So look around for the correct EFS mount point for your Galaxy device.

How to repair EFS partition mount errors on Samsung Galaxy Phones


  1. Go to Sammobile or Samsung-updates website and download an official stock firmware for your phone and flash it in Odin. For Galaxy S2, I flashed the i9100VJMS1 4.1.2 Jelly bean.
  2. Next you need to flash a custom recovery like CWM recovery and also root your device either in recovery or ODIN. For GSII, I used PhilZ CWM.zip recovery which is root ready for your installed firmware. (No need to root ROM separately)
  3. Install ADB on your computer. See How to Install ADB, Fast boot drivers the easier way.
  4. Now power on your device into recovery mode ( Press Power Key+Volume up+Home simultaneously)
  5. Once in recovery, connect your device to the PC via USB cable.
  6. In CWM recovery select “mount and storage > mount /system” (If it indicates “unmount/system” then leave it as that)
  7. On the PC, Open ADB command window and type:

adb shell
mke2fs /dev/block/mmcblk0p1 
mount -w -t ext4 /dev/block/mmcblk0p1

NOTE: If you get this error: can’t find /dev/block/mmcblk0px in /etc/fstab just ignore, reboot device and cross your fingers that it works. After you run the above ADB commands your device should reboot all the way up and Voila! You should be back up and running again.

How to Fix E: failed to mount /efs (invalid argument) in All Samsung Galaxy Phones.If you find that your Power key, Menu and lock screen are not working after this, you are probably stuck in factory mode like I was in this case. To fix a device stuck in factory mode, use the latest version EFS Professional.

TIP: If you are not sure which particular mmcblk0p* EFS mount point to use, find it through ADB. After mounting /system in step 6 above, connect device to PC, Open ADB and type:

adb shell
 (try cat/proc/mount if mount does not work)

A list of the device partitions will be listed. Find which one is the EFS mount point.

DISCLAIMER: This is a technical repair tutorial, Self Tech Genius is NOT Liable for any bricked devices as a result!

IMPORTANT: Repairing EFS mount point error also restored EFS partition data and fixed the Blank IMEI and Unknown Baseband problem on both Galaxy S2 and Samsung Galaxy Note 3. I was hence able to access the network again which was just epic! I can only hope it will also be of great help to many others with the same E: failed to mount /efs (invalid argument) problem.

Found this post helpful kindly share! Just looking for more info to fix your device? Leave your question in the comments below! We will respond as soon as we can.

Happy Geeking!


Charles Kamara
Follow Him!

Charles Kamara

Charles is a PC technician, tech blogger, infopreneur and an avid reader. Writes about tech that interests him most and more importantly to his audience, he offers solid technical experience in easy DIY tech repair guides. A sociable geek who loves to experiment with gadgets.
Charles Kamara
Follow Him!
  • naive

    You bricked my phone!

    • Hello Naive, kindly explain how this happened since this is a repair tutorial and for you to try this fix the phone MUST be in a bricked condition already.

  • Martin

    I have the same error. I flashed a Custom Rom two years ago. About three month ago my telephone just crashed sometimes. I restarted and it worked quite fine. But one month ago it did not start. I was stuck in a bootloop. So I did a wipe and factory reset and installed NeatRom. It worked some days and crashed again and I was at bootloop again. I went into recovery mode and did a backup, wiped and imported the backup and it worked fine again. After a couple of days again crash and bootloop. I did the same, but this time it bootlooped. NeatRom has a NeatRom boot screen, but although I had installed NeatRom, it showed me the “Android” boot screen. So I am stuck in the bootloop since then.
    I did a numerous flash with odin, original stock roms and kernels, nothing worked, still bootloop “android”. I then found out after I flashed the original stock rom, that in the recovery mode it showed “cant mount efs invalid argument”. XDA developers aret very helpful with old telephones, so I am here :) I hope you can help me. I did what you write here, but I cannot access adb. It looks like it does not recognize my phone although drivers are correct installed. Might be better to communicate in Skype, if you want to help me :)

    • Hey Martin, we are sorry for your troubles. These kind of problems are quite common on Samsung devices. Make sure that you have mounted the /system in CWM before trying ADB. Also check that you are using ADB v.1.4.2 instead of previous versions. Download Here After that on your PC, go to Control Panel>System&Security>System. On the left panel open Advanced system settings>Environment Variables.
      On system variables, click and edit the ‘Path‘ variable. Ensure that you have ;C:\adb appended here, if not insert it manually to ensure ADB is being treated as a system variable. The Path should look like this C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\adb Connect your device and launch ADB. Let us know how it goes..

      • kumar

        C:\adb> adb devices
        List of devices attached
        0123456789ABCDEF recovery
        C:\adb> adb shell
        ~ # su
        /sbin/sh: su: not found
        ~ # ls
        boot init sdcard
        cache init.rc sys
        data init.usb.rc system
        datadata proc tmp
        default.prop res ueventd.goldfish.rc
        dev root ueventd.rc
        emmc sbin
        etc sd-ext
        ~ # cd /dev/block/platform
        cd /dev/block/platform
        /dev/block/platform # ls
        ls mtk-msdc.0 mtk-msdc.1
        /dev/block/platform # cd dw_mmc
        cd dw_mmc
        /sbin/sh: cd: can't cd to dw_mmc
        /dev/block/platform #

        My phone is xolo q1010i my cmd.exe shows like that can’t cd could you fix and reply me thanking you

        • Hey Kumar, which problem were you trying to solve on the Xolo device? The “su /sbin/sh: su: not found” tells you that proper root was not found and the next root commands won’t be executed.

  • Martin

    the path look like this:
    C:\ProgramData\Oracle\Java\javapath;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\ATI Technologies\ATI.ACE\Core-Static;C:\Program Files (x86)\Samsung\Samsung PC Studio 3\;C:\Program Files (x86)\Windows Live\Shared;C:\Program Files (x86)\AMD\ATI.ACE\Core-Static;C:\Program Files (x86)\Skype\Phone\;C:\adb

    so adb is added here, and have 1.4.2 , mount system and then start:

    when i write in adb “su” it says “/sbin/sh: su: not found

    i think su means “super user” ? so something is wrong with my root?
    because it says when i “reboot recovery” “root access is missing” no – no – yes root device – no – go back

    so i choose “yes root device” and it restarts. after that i try to reboot into recovery again and it still saying “root access is missing” … so what to do here? :D

  • Martin

    So looks like root is missing…but i thought it is included when i have philz touch 5 and cwm base version v6.0.3.7 ???

    • Your ADB looks well added to the System variables and yes flashing PhilZ CWM recovery (ZIP version) for i9100 roots the stock ROM. Did you flash the ZIP version in stock recovery, using the Odin flashable CWM.tar does not root the phone? Again I recommend you use the new PhilZ CWM6 signed.zip found HERE. Which stock ROM are you using?

  • Martin

    there are so many download links, i really do not know which one i should use???
    i did not flash in stock recovery, i always used odin to flash.

    my stock rom (maybe the wrong one? i do not know): I9100XWLSW_I9100XXMS2_I9100XEULS5_HOME.tar.md5
    philz: PhilZ-cwm6-XWMS2-MOT-5.15.9.tar.md5

    i also have a philz zip: philz_touch_6.48.4-i9100.zip

    what to do now? maybe i start from the beginning with flashing and the correct versions?

    • The stock ROM is just fine, all you need to do to ensure proper root is to find the correct PhilZ CWM Zip compatible with the Kernel of the firmware you downloaded. The LSW part in the above ROM is the Kernel code, now I couldn’t find a rooted zip recovery for that kernel on the XDA post. To be certain, download another firmware like the i9100XWLSN or i9100XWLSE firmware and flash the available compatible PhilZ touch recovery zip on that post.

  • Martin

    Alright. here we go. IT WORKED, big thanks :) here is what i did:
    Stock rom: I9100XWMS1_I9100XXMS4_I9100NEELS1_HOME.tar
    philz: PhilZ-cwm6-XWLSZ-OJC-5.15.9-signed.zip

    and it worked, i got a rooted phone (though i did not have an external card, i flashed with odin a not compatible philz version to get CWM and then flashed the above philz zip with CWM)

    now i did all the adb stuff and all went fine (he found su). i got the error “can’t find /dev/block/mmcblk0px in /etc/fstab”, ignored it and rebooted…now something interesting, it booted and showed me the NeatRom bootscreen??? i was a little bit confused. i crossed fingers and after a couple of minutes it has booted :)))))))))))

    i did a factory wipe / cash wipe and neatrom bootscreen disappeared and it showed me the samsung logo boot screen and booted perfectly.

    so i am happy it is working again. but now i think it is best to delete everything and start with a fresh phone (eg when i connect usb i am seeing a lot of old apps on my phone). how i am doing this?

    • We couldn’t be any happier that you found this article helpful! To clear old log files, you can try wiping the Dalvik Cache in CWM recovery and factory resetting again. Enjoy!!!

      • Ravi

        I am using SM-T211 (Tab 3 7.0) and I have successfully flashed CWM recovery on my tablet and installed ADB on my windows PC as well. I have also flashed original firmware using Odin. But now I don’t know what to do ? So please guide me.

        • If you have already rooted your Tab 3, try the following commands in ADB terminal to get the correct mount point for the EFS partition. After mounting /system in step 6 above, connect device to PC, Open ADB and type:
          adb shell
          (try mount if this does not work)

          • Ravi

            When I type SU it shows “/sbin/sh: su: not found”.
            So what can be the issue ?

  • Which android version? Looks like root is not properly installed. Just bypass the SU command and see if it works. You will need to re-root the tab however to proceed further.

    • Ravi

      I have downloaded Stock Firmware (Android 4.4.2) for SM-T211 from Sammobile and installed using Odin. After installation tab is stuck at SAMSUNG LOGO and when I enter recovery mode it shows E: failed to mount /efs (invalid argument). Now please guide me. What should I do further ?

    • Ravi

      I have downloaded Stock Firmware (Android 4.4.2) for SM-T211 from Sammobile and installed using Odin. After installation tab is stuck at SAMSUNG LOGO and when I enter recovery mode it shows E: failed to mount /efs (invalid argument). Now please guide me. What should I do further ? Should I re-root the device ? If yes then please guide me how to root the device properly.

      • Download this latest rootpackage.zip for Tab 3 and put it at the root of your SD card (not inside any folder). Go to CWM recovery>>Install>>Install from SD card and flash the zip. Some older root exploits had issues rooting some ROMS. Hope that works..

  • Arunkumar

    Hllo friends ,
    i have find one solution for that , that works for me . recently i have thiz same issue in my samsung galaxy star pro . i have tried to install custom rom , but there was boot loop , then i flash my stock rom with odin . then prblm starts . Network wont come , internal sd card wont mount and various prblms , coz my mobile’s EFS folder was erased . then i have find my official efs image by googling . simply flashed that via odin . thats all problem solved . no need to use commands … try thiz method it could be help u . Thanxxx

    • Glad to here from you ArunKumar. You must have been lucky because in most cases flashing any other EFS image does not work since the EFS partition data is specific to each device and flashing another device image means inherating another person’s IMEI number and Mac address instead of repairing the original phone’s EFS data.

  • Mohamed


    Thanks for the guide.
    I have the Unable to mount efs (invalid argument erro) on SG4 GTi 950.
    Steps I followed:

    – Flashed the stock rom:

    – Flash philztouch

    – In Recovery I installed Root-update from SD Card.

    Open ADB mount system

    then I get
    C:\adb>adb devices
    List of devices attached
    4d008d0be78b3009 recovery

    C:\adb>adb shell
    ~ #

    It’s my Understanding that I do not have root?
    But flashing update -root didnt help.

    Any suggestions


    Microsoft Windows [Version 6.1.7601]
    Copyright (c) 2009 Microsoft Corporation. All rights reserved.

    • You can try a newer Philztouch recovery for your Galaxy S4 i9500 running lollipop. Download:
      Flash this rootzip

      • Mohamed

        Is there a speicific stock recovery file i need to use?
        Im still getting
        C:\adb>adb devices
        List of devices attached
        4d008d0be78b3009 recovery

        C:\adb>adb shell
        ~ #

      • No any of them should do. If that does not work you can try flashing a pit file of that particular firmware in Odin to repartition the device and hopefully solve the boot loop.

  • Amrit

    Thanks a lot , it was making me nuts for days. this worked.Thanks again

  • Crina

    Hello, please please guide me how to restore my efs! This is my case:

    I`m new to rooting and installing custom ROMs and in the process I lost my IMEI number ( it just shows a generic one now) .
    My phone was initally from Orange Romania. It was unlocked for UK and it worked for a loong while. It had gingerbread version. I rooted it and added JB neatrom with a syiah kernel. All seemed alright except I had no service anymore. I tried going back to quite a few stock firmwares for UK T Mobile ( I use Tmobile pay as you go). Some of them sent my phone into bootlooping. The current version I have is this one: http://www.sammobile.com/firmwares/download/29852/I9100XXMS7_I9100OXAMS7_XEO/ and it is sucessfully rooted.

    Before adding the JB NeatROM, I used GSII repair and made a backup of the efs. I have a file on my computer:
    efs_save.tar from 22 september.
    On the phone, just in My files I have these 2: efsdev-mmcblk0p1.img.gz & efsbackup.tar.gz from 23 sept
    All these should be related to the good backup.

    A few days later, when I had a different ROM and the network problem I did another efs backup , also using GSII repair so in my phone , in the GSII_repair folder there are : efs_save.tar & efs_save.tar.gz from 25 sept but these files are bad I suppose.

    I took a look at post #2 here: http://forum.xda-developers.com/galaxy-s2/help/efs-restore-backup-t1377105 but it seems complicated as I never used ADB before.

    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 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 in that folder.

    Can you please help me fix my phone? If you can please explain step by step it will be greatly appreciated ! Otherwhise Im hopeless….

  • Crina the fact that you have a back up of the original IMEI is good and that’s all you may need to restore the network problem using the same GSII repair tool. Are you still stuck at boot loop?

    • crina

      No, the phone is now booting. However the firmware I now have is different from the one I had when I made the backup. Would that be a problem?

      I was thinking of using EFS professional to restore it afterall.

      Thank you

      • Charles Kamara

        The EFS partition is not part of the flashable firmware so any ROM should work. Now that you have the firmware rooted, install Busy box from play store, open&select install. The same GSII Repair tool is simple enough to restore the original IMEI. Install GSII repair on phone, Locate the folder ‘GSII repair’ on the internal storage. Transfer the very first backed up IMEI files from PC to this folder. Open GSII repair tool, on ‘save/restore’ tab select the second option ‘Restore Previous save’ and Reboot.

        • crina

          Thank you. What should I use the Busybox for ? Hopefully GSII will work.

          • Charles Kamara

            Some root apps need busy box to work correctly. You can then try EFS Professional with your very first backup. Move the backup to EFS pro&restore.

  • Muhammad Kudoos


    Does anyone know the EFS mount point for the Samsung Tab 7.0 Plus (GT-P6200)?

    Thanks in advance.

    • Joe Bradon

      If you have access to the system, root the phone, turn on usb debugging in settings connect it to a PC and type these commands in ADB shell.
      adb shell
      (try mount if this does not work)
      All your device mount points will be listed including EFS mount point.

      You can also use the same commands to find mount points in terminal emulator if your device is rooted.

  • Kushal Vartak

    plz help me ” cant cd to cd /dev/block/platform”

    • Charles Kamara

      Which adb command were you trying to execute? Ensure the device has proper root access.

  • Nadir Malik

    hi admin…i have samsung galaxy grand neo GTi9060…yesterday i was opening wifi then my phone restart and stuck on bootloop..when i enterd in recovery it says ..E: failed to mount /efs (invalid argument)..in red..

    i flash with stock rom even i flashed with repair firmware to repartition..but no luck..

    then i found ur blog..seems like its working for many..i tried whatever u said..but in adb command it says.. su;permission denied..

    then i flashed..GenNxt_PreRooted_GT-I9060_BalliBoxer.zip..

    but same error..after this i tried..UPDATE-SuperSU-v2.46.zip

    but same error…
    Any Suggesion…….

    kindly help me in this matter…

  • Nadir Malik

    hello sir…i installed..TWRP-…now its rooted…but my problem not solved..still bootloop..here is the adb command log…

    C:adb>adb shell

    ~ # ←[6nsu


    root@android:/ # mke2fs /dev/block/mmcblk0p5

    mke2fs /dev/block/mmcblk0p5

    mke2fs 1.41.14 (22-Dec-2010)

    Warning: the fs_type small is not defined in mke2fs.conf

    Filesystem label=

    OS type: Linux

    Block size=4096 (log=2)

    Fragment size=4096 (log=2)

    Stride=0 blocks, Stripe width=0 blocks

    1280 inodes, 5120 blocks

    256 blocks (5.00%) reserved for the super user

    First data block=0

    Maximum filesystem blocks=8388608

    1 block group

    32768 blocks per group, 32768 fragments per group

    1280 inodes per group

    Writing inode tables: done

    Writing superblocks and filesystem accounting information: done

    This filesystem will be automatically checked every 19 mounts or

    0 days, whichever comes first. Use tune2fs -c or -i to override.

    root@android:/ # mount -w -t ext4 /dev/block/mmcblk0p5

    mount -w -t ext4 /dev/block/mmcblk0p5

    CANNOT LINK EXECUTABLE: cannot locate symbol “__strchr_chk” referenced by “mount


    1|root@android:/ # mount -w -t ext4 /dev/block/mmcblk0p5

    mount -w -t ext4 /dev/block/mmcblk0p5

    CANNOT LINK EXECUTABLE: cannot locate symbol “__strchr_chk” referenced by “mount


    1|root@android:/ #

    tell me sir what i m doing wrong…
    thanks in advance…

    • Charles Kamara

      Malik did you mount the /system in CWM before using ADB (Refer step 6. above).If you did and still getting the same error, make sure that ‘mmcblk0p5′ is the correct mount point for your Galaxy Grand Neo.

      • Roberto Carrillo

        Hello, i have the same error
        I double checked and the mount point it is mmcblk0p5, but i’m not able to access, what could be done?
        thanks in advance

        • Charles Kamara

          Hey Roberto, which part are you not able to access? Which Samsung model? sorry for the delay in response

  • PM Astiasarán

    I can´t say how I aprecciate your help, it was fantastic and save me. My sincerest congratulations for your work.

    • Charles Kamara

      Thank you for your feedback. We are glad it worked out for you. Kindly share!!!

  • Bryan Truaent Bryant

    how can I use EFS professional to get my phone out of factory mode?

    • EFS professional program has this function under Qualcomm tools. Optionally you can use terminal IDE or ADB to exit factory mode.

      • Colin

        Hi Charles,
        EFS Professional keeps trying to search for my phone (S3 GT-i9300) but can’t find it. Would it be because I need install usb drivers ?
        – Cheers!

  • Patrick Roberts

    Hello, why am i getting “/sbin/sh: su: not found” when i enter the su command?

    • Root access is not properly installed on your device. Which device? You may try rooting it again

    • Which device? Root access is not properly installed on your device. You may try rooting it again.

      • Patrick Roberts

        Thanks Charles, i suspected that much…its a Samsung Galaxy Note 2 international version. Could i root this in its present state on a mac? Its stuck in boot.

        • Yes check Step 2. Install a custom recovery and flash the root.zip in custom recovery or through ODIN (PDA menu) with a .tar root image file.

  • Noyel

    what problem?
    /sbin/sh: su: not found

    • SU is super user or root user utility installed on the device. If ADB cannot find it, it means root access is not properly installed or needs update. Try rooting the phone again (usually the superuser root.zip file has various versions for the same phone. You may try a different one but ensure it’s for the same device model. Hope that helps

    • Mateusz

      Try mounting /system

  • Syirul Syaff

    its worked. but after do this all, my note 2 show “not registered on network”. i tried anything and still same. anyone help :(

    • Does it show the original IMEI? What about the Baseband version in phone settings>about phone?

  • Ф L V C K O

    Was experiencing exactly the same problem with my sister’s SII, thought I am gonna explode, while being searching for solution, and here it was! THANK YOU VERY MUCH, MY FRIEND, YOU HELPED ME A LOT!!!

  • Ugonna Nwosu

    I have the Note 4 and having problems. I have ODINed to the latest firmware, rooted with Chain Fire root method, and installed TWRP. However the su reports as not found. I’d really appreciate any help to restore my device. This is stopping me from doing a factory reset. I have also tried re-partition and NAND wipe when installing custom firmware along with Tmobile PIT file. I’m on Lollipop 5.1.1 Tmobile SM-N910T. When I try to do a factory reset I get unable to mount storage, unable to mount data and cache. And the bootloop continues. Please help!

    • Hey Ugonna apologies for the delay, haven’t been around for a bit. Were you able to resolve your issue? Check if you are able to obtain root access by flashing the root files in custom recovery instead. The /data partition seems to be damaged rather than the /efs partition, Flashing the correct PIT file for your Note 4 model file should repartition and correct this. If you choose to use this method, change the mount point to match the /data partition instead in the next steps).

  • Urs

    Hi, I had the problem on a Samsung Galaxy Alpha G850F. Finaly I was successful with these steps (all in recovery mode)
    – flashing with the latest stock rom from sammobile (using ODIN)
    – flashing costom rom TWRP
    – rooted the device with adb sideload (UPDATE-SuperSU-v2.76-20160630161323.zip)
    Then I was able to perform the suggested commands:
    adb shell
    (su didn’t worked)
    mke2fs /dev/block/mmcblk0p3
    mount -w -t ext4 /dev/block/mmcblk0p3

    • Thank you Urs for the valuable input and positive feedback. Glad you succeeded with this.

  • Thanks for the great feedback Pat. Don’t forget to bookmark our website.

  • kyo379

    hi friend, sorry for my engilsh, but i dont know how say you thankyou very much, this finally works is great, thankyou, thankyou, thankyou.

    • Thanks Kyo379, your English is just fine. We are glad to help. Kindly share and always come back to our website for more!

  • Andrew Loehr

    Hi, i last week tried to put a custom rom on my sm-n920R4 note 5 , the rom worked but was not intended for my variant(i did not know that at the time). Now i have no network ! I have been trying to fix this for a week with no luck. It doesnt read my sim card ,and in my settings under more network connections mobile networks is gone completly , imei shows blank not null . I tried flashing back stock rom and many other ones and on the stock rom the phone reboots every 25seconds , on a custom rom it will stay on fine but no network . I have tried your method and there is no mmcblk0p file in there , when i get to dev/block/platform all there is is a file called 15570000.ufs and in that are all sda files like sda3 sda4 etc… Any advice ?im about to give up…

    • Hi Andrew, looks like the /efs partition got messed up. Without a previous IMEI backup (basically the efs folder) it’s quite frustrating to restore the original EFS configurations especially on Exynos chipsets. The next logical attempt would be to try repartation the device using it’s original .PIT file (You may ODIN flash a four-part stock firmware file which includes the PIT file) This might resolve the frequent reboots on stock ROM and then you could proceed with restoring the network signal.

      • Andrew Loehr

        Thank you for your reply , i have tried to get the pit file off of my phone with no luck either , i have ALL the stock firmwares for my variant of the note 5 lol .

      • Andrew Loehr

        I finally got the phone working , after getting a new one through the insurance lol . I had left the phone in a drawer for a few days and it died completely , i flashed a rom and a a stock modem and it came on with signal and reading the sim card ! So i guess the battery needed to be pulled , which i tried to do but the note 5 doesnt have a removable battery . Also i dont think it uses mmcblk files , i couldnt find any on it when i looked after i got it running . Thank you for your help !

        • That’s great that you got it working again! Cheers!!!

      • Kishan Vaghasia

        yea it contains 4 files in zip but i dont know wheere to load the in odin

    • Ricardo Lourenço

      try the whole methode but with that sda3 file, and go furhter ignoring error messages and stuff

      • Ricardo Lourenço

        newer devices has another files. i also did the same on a s7 edge.
        when you enter in recovery and try to backup, you get a message log like this:

        I:InfoManager saving ‘/usb-otg/TWRP/BACKUPS/988678505047434958/2016-09-08–00-26-52/data.info’
        I:createTarFork() process ended with RC=0
        I:Partition Backup time: 0
        * Generating md5…
        I:MD5 for /usb-otg/TWRP/BACKUPS/988678505047434958/2016-09-08–00-26-52/data.ext4.win: 0f343b0931126a20f133d67c2b018a3b data.ext4.win

        * MD5 Created.
        Average backup rate for file systems: 7 MB/sec
        Average backup rate for imaged drives: 6 MB/sec
        [3365 MB TOTAL BACKED UP]
        Updating partition details…
        I:Data backup size is 0MB, free: 25077MB.
        I:Can’t probe device /dev/block/sda3
        Failed to mount ‘/efs’ (Invalid argument)
        I:Actual block device: ‘/dev/block/sda3′, current file system: ‘ext4′
        I:Unable to mount ‘/external_sd’
        I:Actual block device: ”, current file system: ‘vfat’
        I:Unmounting main partitions…
        I:Copying file /tmp/recovery.log to /usb-otg/TWRP/BACKUPS/988678505047434958/2016-09-08–00-26-52/recovery.log

        Above and below

        Failed to mount ‘/efs’ (Invalid argument),

        you have this message:

        I:Can’t probe device /dev/block/sda3

        I:Actual block device: ‘/dev/block/sda3′, current file system: ‘ext4′

        try a backup to make sure if in your device is the sda3′ or other……

        • Thanks for the input there Ricardo. Andrew should probably try this on his Note 5.

  • Henry Sigas

    Hi, charles… I following your method from null/null, unknown baseband..
    The baseband came up but the imei 0049…… Stil got no registered network. Then i restart it.. Next happen my note 3 become stuck on logo note n900 it didnt get thru the samsung booting menu.. I flash it stock firmware it stay the same..
    E. Failed to mount…..
    Please help..

    • Check first which partition has failed to mount. /efs /data or /cache?

      • Henry Sigas

        how can i check which is failed to mount? myb with app or else..

        • It should show which partition has failed when you enter stock recovery. Are you able to access stock recovery?

      • Adib Dota

        my phone cant mount cache

  • SaM PaR

    Hey Charles. When i run the adb shell command,
    i get error: device (null) not found.
    any ideas?

    • Ensure you have all proper device drivers installed, try reinstalling the drivers.

      • SaM PaR

        drivers are reinstalled 2 times and theyre fine : /
        Is there a chance that this works only on phones and not tablets?

  • egidiu cristian

    hi what should i do if it doesn’t find my device??

    • Ensure all proper device drivers have installed and use original USB cable.

  • egidiu pista

    Hey Charles. When i run the adb shell command,
    i get error: device (null) not found.
    any ideas?

    • Something to do with proper drivers&device connection. Ensure all proper device drivers have installed and use original USB cable.

    • Ensure all proper device drivers have installed and use original USB cable.

    • 01101001b

      Try a different usb cable.

  • 01101001b

    Hi! Your information happened to be quite useful in my case! My phone -a GT-N7100- suffered a catastrophic failure due to a wasted battery and several partitions went corrupted (system, data, cache), even EFS went affected.

    I followed your instructions (searching beforehand the right mmcblk0p* EFS mount point for a Note 2 N7100 -that happened to be the same a Note 3 uses-) and voilà! It came to life!

    My phone and I are quite thankful! :-)

  • Mark Strumolo

    Hi! Im new to all this but I am trying to fix the, “e: failed to mount /efs (invalid argument)” issue with my Note 2. I have ADB on my computer and TWRP on my phone. I flashed the factory firmware and rooted the phone. I now have the phone in recovery (TWRP) mode and plugged into the computer via usb with ADB running in the PowerShell window. When I type in “adb devices,” my phone is there. However, when I type “adb shell,” nothing happens except the following on the next line: “~ # ^[[6;5R ” I have no idea what this means or what to do next. I have tried doing this both with the phone in recovery mode with nothing selected and with “mount, system” selected and I get the same result. Does anyone have any ideas that might get me past this and to the next step–or at least let me know what the code that I’m getting means? Thanks!

    • The adb shell command is meant to run the rest of commands with root priviledges. Kindly reroot your device probably using a different rooting method to get past the error. the shell is not able to find proper root on your device. Regards

      • Mark Strumolo

        Thanks for your response! Do you recommend a particular method for rooting my phone. Because I can’t boot it, I can’t tell if it is or isn’t…kinda busy right now but I will try again when I get a chance…Thanks, Mark

  • roshan

    hey please give me link for philZ cwm Recovery

  • Nigel M Hall

    I found a solution to this problem! (I have a Note 2 N7105).
    Follow this quick guide: https://forum.xda-developers.com/note-2-sprint/help/quick-fix-guide-to-corrupted-efs-t2889668
    This will create a generic EFS file on your device, and it should boot past the Samsung logo once your done (it did for me).
    When you reboot, you will see yellow text on your screen, which means your in Factory mode.

    To get rid of the yellow txt, use this YouTube vid:

    Then, for your own sakes, BACKUP YOUR EFS file using this handy YouTube guide: https://www.youtube.com/watch?v=2F8qhWlaQ_8

  • Jaymin

    okay, I installed CWM v6.0.1.9 and flashed the stock rom, yet still when i mount system it doesnt connect with my comuputer, ADB says device not connected. I have installed adb and even rooted the device. Its a GT-N8000. What else can i do?