[HOW TO] Check your filesystem (a la 'fsck')

ViperGeek · Feb 25, 2013

I've been having lots of trouble with my SD and local filesystems getting corrupted, which in turn has been causing the flush-179 process to go ballistic (100% CPU loop, reboot hangs, etc.). If only there was a way to run a quick FSCK(8) on my Android's unmounted filesystems to check for problems. Well, there is!

This may be old, old news to some of the more seasoned OS hackers, so please be kind with any negative feedback about it being intuitively obvious. It wasn't to me, but after some research and testing, I've come up with these simple steps:

Boot into Recovery

Connect via USB to ADB shell

Code:

   C:\Scratch\Android> [B]adb devices[/B]
   C:\Scratch\Android> [B]adb shell[/B]

Mount /system and /data to determine the /dev/block names, then umount each

Code:

   ~ # [B]mount /system[/B]
   ~ # [B]mount /data[/B]
   ~ # [B]df[/B]
Filesystem           1K-blocks      Used Available Use% Mounted on
tmpfs                   308620        64    308556   0% /dev
/dev/block/mmcblk0p27
                        295509    121021    159231  43% /cache
/dev/block/mmcblk0p26
                       1184268    848052    276060  75% /data
/dev/block/mmcblk0p25
                        562384    461416     72400  86% /system
   ~ # [B]umount /system[/B]
   ~ # [B]umount /data[/B]

Run e2fsck against each /dev/block filesystem

Code:

   ~ # [B]e2fsck -n /dev/block/mmcblk0p25[/B]
e2fsck 1.41.6 (30-May-2009)
/dev/block/mmcblk0p25: clean, 4168/35760 files, 117605/142847 blocks
   ~ # [B]e2fsck -n /dev/block/mmcblk0p26[/B]
e2fsck 1.41.6 (30-May-2009)
/dev/block/mmcblk0p26: clean, 7173/75200 files, 216745/300799 blocks
   ~ #

The 'e2fsck' command takes the same command-line switches as UNIX FSCK(8), so you can be as creative and daring as you need.

- Dave

robcop19 · Apr 25, 2013

some help

ViperGeek said:
I've been having lots of trouble with my SD and local filesystems getting corrupted, which in turn has been causing the flush-179 process to go ballistic (100% CPU loop, reboot hangs, etc.). If only there was a way to run a quick on my Android's unmounted filesystems to check for problems. Well, there is!

This may be old, old news to some of the more seasoned OS hackers, so please be kind with any negative feedback about it being intuitively obvious. It wasn't to me, but after some research and testing, I've come up with these simple steps:

Boot into Recovery

Connect via USB to ADB shell

Code:

C:\Scratch\Android> [B]adb devices[/B] C:\Scratch\Android> [B]adb shell[/B]

Mount /system and /data to determine the /dev/block names, then umount each

Code:

~ # [B]mount /system[/B] ~ # [B]mount /data[/B] ~ # [B]df[/B] Filesystem 1K-blocks Used Available Use% Mounted on tmpfs 308620 64 308556 0% /dev /dev/block/mmcblk0p27 295509 121021 159231 43% /cache /dev/block/mmcblk0p26 1184268 848052 276060 75% /data /dev/block/mmcblk0p25 562384 461416 72400 86% /system ~ # [B]umount /system[/B] ~ # [B]umount /data[/B]

Run e2fsck against each /dev/block filesystem

Code:

~ # [B]e2fsck -n /dev/block/mmcblk0p25[/B] e2fsck 1.41.6 (30-May-2009) /dev/block/mmcblk0p25: clean, 4168/35760 files, 117605/142847 blocks ~ # [B]e2fsck -n /dev/block/mmcblk0p26[/B] e2fsck 1.41.6 (30-May-2009) /dev/block/mmcblk0p26: clean, 7173/75200 files, 216745/300799 blocks ~ #

The 'e2fsck' command takes the same command-line switches as UNIX FSCK(8), so you can be as creative and daring as you need.

- Dave

on my phone i have a fiel called fsck.exfat and fsck_msod i think and im trying to run one (though not sure what the difference is) to fix some corrupted files in data internally. im trying to see if the file can be run through recovery without putting it through adb to unmount the data. im not too sure how to figure out what the data block is called because when i rum the mount i get a ton of different blocks (about 32 of them).
im trying to clean up the lost+found files i have and i have 3 of from a corrupted nandroid

ViperGeek · Apr 25, 2013

robcop19 said:
on my phone i have a fiel called fsck.exfat and fsck_msod i think and im trying to run one (though not sure what the difference is) to fix some corrupted files in data internally. im trying to see if the file can be run through recovery without putting it through adb to unmount the data. im not too sure how to figure out what the data block is called because when i rum the mount i get a ton of different blocks (about 32 of them).
im trying to clean up the lost+found files i have and i have 3 of from a corrupted nandroid

Hi Rob.

I'm not sure if I can be of any specific assistance. exFAT is a type of filesystem format, like UNIX/Android ext3 and ext4, but beyond that, I couldn't tell you what those programs do. I do know that on some operating systems, the only way to fix the file chains and blocks is to make sure it's unmounted in single user mode. ADB is the closest we Android guys can get to UNIX single user mode without some clever Recovery Mode ZIP file programming.

– Dave

robcop19 · Apr 25, 2013

alrighty

ViperGeek said:
Hi Rob.

I'm not sure if I can be of any specific assistance. , but beyond that, I couldn't tell you what those programs do. I do know that on some operating systems, the only way to fix the file chains and blocks is to make sure it's unmounted in single user mode. ADB is the closest we Android guys can get to UNIX single user mode without some clever Recovery Mode ZIP file programming.

– Dave

well thank you for at least writing back on it. im not sure how to run adb let alone run the progrma to try and fix this but i will be learning up on it

ViperGeek · Apr 25, 2013

robcop19 said:
well thank you for at least writing back on it. im not sure how to run adb let alone run the progrma to try and fix this but i will be learning up on it

ADB isn't all that difficult to use. Here's a good primer on it:

http://droidlessons.com/how-to-install-adb-on-a-windows-7-pc/

Once installed, just boot your phone into Recovery (power off completely, then power on with the Vol Down key held, then select RECOVERY). Once it's sitting there, connect your phone to the PC via USB, wait for Windows to find the right drivers, and you're connected. 'adb devices' should list your phone in the "List of devices attached", after which you're good to go.

– Dave

ps. I've not tried it personally, but there's supposedly a "universal USB driver" available here:

https://plus.google.com/103583939320326217147/posts/BQ5iYJEaaEH

robcop19 · Apr 25, 2013

wow

ViperGeek said:
ADB isn't all that difficult to use. Here's a good primer on it:

Once installed, just boot your phone into Recovery (power off completely, then power on with the Vol Down key held, then select RECOVERY). Once it's sitting there, connect your phone to the PC via USB, wait for Windows to find the right drivers, and you're connected. 'adb devices' should list your phone in the "List of devices attached", after which you're good to go.

– Dave

ps. I've not tried it personally, but there's supposedly a "universal USB driver" available here:

Wow thank you very much for the help youre giving me I will see if i can go and start finding a solution

irishpanther · Jun 19, 2013

ViperGeek said:
The 'e2fsck' command takes the same command-line switches as UNIX FSCK(8), so you can be as creative and daring as you need.

- Dave

I figured this out about a week ago now I guess and did indeed find that there were corrupted partitions. My phone had been acting up for several weeks before and it pretty much unusable now. I do manage to clean system and data up, and was even able to flash a new ROM which I hadn't been able to, they'd always abort.

I have a question though, is this only good for ext2 partitions? I have the same version as shown in the tutorial and if you run 'e2fsck -V' the output makes me think that maybe it's not happy checking ext3 and ext4 partitions and that's why i was popping up errors, or at least that's why even when i fixed errors it maybe wasn't really fixing the issue.

Thanks.

I've got a different phone, but a search brought me here to this thread. I think my issues though are more corrupted memory rather than device specific so hope you don't mind my post here.

bsmitty83 · Jun 19, 2013

I think this will answer your question

http://linux.die.net/man/8/fsck.ext3

(It should be good for all ext partitions)

Sent from my Galaxy Nexus using Xparent Cyan Tapatalk 2

annur · Oct 2, 2013

ahh the good old fsck
glad i found this thread
thanks a lot mannnn

ViperGeek · Oct 24, 2013

One more helpful tidbit.

Even if you run 'e2fsck -n' and find a "clean" file system, it may be useful to force a scan via 'e2fsck -f'. This just happened to me. I had something funny going on, and so rebooted into recovery and checked my file systems. Everything was cool like Fonzie, which I didn't believe, and so I used 'e2fsck -f' and found lots of fuglies that got fixed.

Be careful running -f on a cross-linked file system like the /data partition on a Galaxy S3/S4. It can have the tendency to unlink the elfin magic Samsung used and make a mess.

- Dave

ViperGeek · Oct 24, 2013

(Double-tap post deleted)

birdie · Dec 8, 2013

This will not work with stock Android - default boot to recovery doesn't enable adb - you have to have CWM for that.

So, the questions remains - how can I run e2fsck without rooting my phone (and possibly voiding its warranty)?

rod.gui · Dec 28, 2013

How do I get the Moto X in Recovery mode to accept the adb command?
Because when I put in Recovery (Android Robot lying down) mode, the command adb and fastboot are not recognized.

PRose61 · May 18, 2016

Can this be done in terminal? And would I need su?

tomiga · May 19, 2016

PRose61 said:
Can this be done in terminal? And would I need su?

Yes, this can be done in terminal on the phone itself. You do need root/su.

krashd · Aug 19, 2016

ApTeM said:
This will not work with stock Android - default boot to recovery doesn't enable adb - you have to have CWM for that.

So, the questions remains - how can I run e2fsck without rooting my phone (and possibly voiding its warranty)?

Is this why I get can't read '/etc/fstab': No such file or directory?

I'm using a stock Samsung S2, but it is rooted and has superuser and busybox.

cohosalmon · Aug 30, 2017

Code:

ViperGeek said:
I've been having lots of trouble with my SD and local filesystems getting corrupted, which in turn has been causing the flush-179 process to go ballistic (100% CPU loop, reboot hangs, etc.). If only there was a way to run a quick on my Android's unmounted filesystems to check for problems. Well, there is!

This may be old, old news to some of the more seasoned OS hackers, so please be kind with any negative feedback about it being intuitively obvious. It wasn't to me, but after some research and testing, I've come up with these simple steps:

Boot into Recovery

Connect via USB to ADB shell

Code:

C:\Scratch\Android> [B]adb devices[/B] C:\Scratch\Android> [B]adb shell[/B]

Mount /system and /data to determine the /dev/block names, then umount each

Code:

~ # [B]mount /system[/B] ~ # [B]mount /data[/B] ~ # [B]df[/B] Filesystem 1K-blocks Used Available Use% Mounted on tmpfs 308620 64 308556 0% /dev /dev/block/mmcblk0p27 295509 121021 159231 43% /cache /dev/block/mmcblk0p26 1184268 848052 276060 75% /data /dev/block/mmcblk0p25 562384 461416 72400 86% /system ~ # [B]umount /system[/B] ~ # [B]umount /data[/B]

Run e2fsck against each /dev/block filesystem

Code:

~ # [B]e2fsck -n /dev/block/mmcblk0p25[/B] e2fsck 1.41.6 (30-May-2009) /dev/block/mmcblk0p25: clean, 4168/35760 files, 117605/142847 blocks ~ # [B]e2fsck -n /dev/block/mmcblk0p26[/B] e2fsck 1.41.6 (30-May-2009) /dev/block/mmcblk0p26: clean, 7173/75200 files, 216745/300799 blocks ~ #

The 'e2fsck' command takes the same command-line switches as UNIX FSCK(8), so you can be as creative and daring as you need.

- Dave

Thank you for your very well done post. I also realize that this thread is very old. Still it is the best I have found after days of looking. And finally, I have a different phone. Having said that perhaps someone might help.

My phone is a Galaxy S5 Verizon SM-G900V running KitKat 4.4.4. I have root on the phone, but am running stock Verizon Kitkat with stock recovery.

So I have used ADB by plugging in my phone via USB to my Windows computer. I can get root in ADB and find the /data filesystem and its /dev/block/... device. But when I try to

Code:

umount /data

I get a response that the filesystem is busy. This makes sense.

I have booted into recovery via VOL UP + HOME + POWER and it takes me to the RECOVERY menu. But the only option that connects with my ADB shell is "apply update from ADB". When you use the command

Code:

ADB devices

, my phone shows up, but as "phoneid" sideload, and

Code:

ADB shell

exits immediately.

I have also tried to use a terminal shell and then su to root. Again I cannot umount /data since it is busy. (Of course it is, I am using it...)

And finally I have tried

Code:

touch /forcefsck

to create that file in the root directory. This is supposed to force a fsck during boot up. But the root directory (/) is read only. So you can't write the file to it.

I am at my wits end. What I really need to do is mark the /data filesystem as dirty and have the system check it on reboot. But I can't find anyway to do it.

So if anyone can help, I would be very grateful
Joe

SoulSnatchr · Aug 1, 2023

ViperGeek said:
I've been having lots of trouble with my SD and local filesystems getting corrupted, which in turn has been causing the flush-179 process to go ballistic (100% CPU loop, reboot hangs, etc.). If only there was a way to run a quick FSCK(8) on my Android's unmounted filesystems to check for problems. Well, there is!

This may be old, old news to some of the more seasoned OS hackers, so please be kind with any negative feedback about it being intuitively obvious. It wasn't to me, but after some research and testing, I've come up with these simple steps:

Boot into Recovery

Connect via USB to ADB shell

Code:

C:\Scratch\Android> [B]adb devices[/B] C:\Scratch\Android> [B]adb shell[/B]

Mount /system and /data to determine the /dev/block names, then umount each

Code:

~ # [B]mount /system[/B] ~ # [B]mount /data[/B] ~ # [B]df[/B] Filesystem 1K-blocks Used Available Use% Mounted on tmpfs 308620 64 308556 0% /dev /dev/block/mmcblk0p27 295509 121021 159231 43% /cache /dev/block/mmcblk0p26 1184268 848052 276060 75% /data /dev/block/mmcblk0p25 562384 461416 72400 86% /system ~ # [B]umount /system[/B] ~ # [B]umount /data[/B]

Run e2fsck against each /dev/block filesystem

Code:

~ # [B]e2fsck -n /dev/block/mmcblk0p25[/B] e2fsck 1.41.6 (30-May-2009) /dev/block/mmcblk0p25: clean, 4168/35760 files, 117605/142847 blocks ~ # [B]e2fsck -n /dev/block/mmcblk0p26[/B] e2fsck 1.41.6 (30-May-2009) /dev/block/mmcblk0p26: clean, 7173/75200 files, 216745/300799 blocks ~ #

The 'e2fsck' command takes the same command-line switches as UNIX FSCK(8), so you can be as creative and daring as you need.

- Dave

Do these procedures require root or can be done from stock recovery?

ViperGeek · Aug 1, 2023

SoulSnatchr said:
Do these procedures require root or can be done from stock recovery?

Hi SoulSnatchr.

AFAIK, the Android Debug Bridge (ADB) always runs as single-user root.

- Dave

[HOW TO] Check your filesystem (a la 'fsck')

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