[Q] lost+found directory in /data - Android Q&A, Help & Troubleshooting

Hi, I'm using an LG Optimus L9 and running 4.3 bassed PAC-man rom.
The internal memory is 4GB and after installing a few apps, I started getting "Not enough storage space" warnings.
So, I checked the /data folder and found that there's directory called lost+found which is taking up a lot of space (Above 1.5GB).
I tried deleting files using ES Explorer with the data folder mounted as R+W, but it says "error deleting files"
Is it safe to delete the lost+found folder?
And if yes, how can I delete it since I'm unable to delete it with a file explorer app.
It would be really great if could recover thelost internal memory

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void00 said:
Hi, I'm using an LG Optimus L9 and running 4.3 bassed PAC-man rom.
The internal memory is 4GB and after installing a few apps, I started getting "Not enough storage space" warnings.
So, I checked the /data folder and found that there's directory called lost+found which is taking up a lot of space (Above 1.5GB).
I tried deleting files using ES Explorer with the data folder mounted as R+W, but it says "error deleting files"
Is it safe to delete the lost+found folder?
And if yes, how can I delete it since I'm unable to delete it with a file explorer app.
It would be really great if could recover thelost internal memory
Click to expand...
Click to collapse
I don't think there is a problem doing that and change the permission to rwx-rwx-r try and report

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sangalaxy said:
I don't think there is a problem doing that and change the permission to rwx-rwx-r try and report
Click to expand...
Click to collapse
I tried deleting the folder through adb shell.
Issued following commands:
adb shell
su
# cd /data
# rm -r lost+found
Click to expand...
Click to collapse
The output was "rm failed for lost+found. Operation not permitted"
Also tried this mounting /data as rw but no luck.
Tried chmod 775 on lost+found but no luck either.
Always getting operation not permitted message.

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void00 said:
I tried deleting the folder through adb shell.
Issued following commands:
The output was "rm failed for lost+found. Operation not permitted"
Also tried this mounting /data as rw but no luck.
Tried chmod 775 on lost+found but no luck either.
Always getting operation not permitted message.
Click to expand...
Click to collapse
try r+w+x

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sangalaxy said:
try r+w+x
Click to expand...
Click to collapse
Still getting the same error. Operation not permitted.

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void00 said:
Still getting the same error. Operation not permitted.
Click to expand...
Click to collapse
may be something preventing it
try a reset and simply format the data in cwm do backup first

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sangalaxy said:
may be something preventing it
try a reset and simply format the data in cwm do backup first
Click to expand...
Click to collapse
Using TWRP.
If I backup first, it will also back up the lost+found data
And restoring data will bring it back.
I did format data and system before flashing the rom. So I don't know why the lost+found has so large size.
What should I do?

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void00 said:
Using TWRP.
If I backup first, it will also back up the lost+found data
And restoring data will bring it back.
I did format data and system before flashing the rom. So I don't know why the lost+found has so large size.
What should I do?
Click to expand...
Click to collapse
ok so don't backup
if anything goes wrong you can still flash the stock right??

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sangalaxy said:
ok so don't backup
if anything goes wrong you can still flash the stock right??
Click to expand...
Click to collapse
hmm, i'll try flashing CWM and then do a format of every partition and freshly flash the rom.
Will report back if there's the same problem.
UPDATE:
Formatted all the partitions including /data/media using CWM
Did a fresh install of rom.
I've got my internal memory back
Thanks!

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my 2 cents...
my 2 cents... I've opened the lost+found folder with the file manager (this https://play.google.com/store/apps/details?id=com.rhmsoft.fm), after enabling the root explorer functionality, and deleted a bunch of the biggest files, just checking they were at least 2-3 months old. Rebooted to make sure everything is fine and dandy, and now I've got enough free space, sun is chirping, birds are shining, life is beautiful :silly: :victory:

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fabiosirigu said:
my 2 cents... I've opened the lost+found folder with the file manager (this *edited original link*), after enabling the root explorer functionality, and deleted a bunch of the biggest files, just checking they were at least 2-3 months old. Rebooted to make sure everything is fine and dandy, and now I've got enough free space, sun is chirping, birds are shining, life is beautiful :silly: :victory:
Click to expand...
Click to collapse
I was having the same problem. My phone is Samsung Galaxy S2 (GT-i9100). I was on stock Jellybean. But it was starting to feel sluggish and slow. So, having heard about the new Android Kitkat's lower memory requirements and smoother performance, i decided to install Cyanogenmod 11 on it.
Installation was not without problems. At first i flashed Clockworkmod Recovery 6.0.2.9. The phone bricked into a bootloop with a yellow triangle on it. Flashing the Cyanogenmod 11 resulted an error of "Status 7". So i searched for the latest Clockworkmod Recovery, which was at 6.0.4.5. After flashing the 6.0.4.5, Cyanogenmod 11 installed successfully. Performance was really smooth. No lags, no jitter, and everything worked like a charm.
The problem started when i re-installed my applications. Suddenly i got a message of "insufficient storage". This has never happened before. Note, that i previously had large games on my phone like Real Racing 3 and Bard's Tale. This time, i haven't even installed those large games. So i looked at my Storage, and found out that i only had 141mb of free space. But the weird thing is, my reported Apps was only 353mb, from 1.97GB internal storage. So there was over 1GB of storage just vanished.
I browsed for a solution to this problem, and landed on this thread. After reading reply from fabiosirigu, i decided to brave myself, and deleted the content of the lost+found folder (but not the folder itself). I accessed the folder with the built-in File Manager from Cyanogenmod, and set it to "Root Access Mode", and select all folder in the folder, and deleted it. The deletion took quite a few minutes, which felt like ages. Just sat on my bed, crossed my fingers, hoped that nothing will go wrong.
After the deletion, i rebooted my phone. the cyanogenmod logo appeared, and the system booted as usual. I just exhaled a massive sigh of relieve. I went straight to the internal storage, and now it is showing the correct report, 1.67GB of free space.
Thank you for your reply fabiosirigu. Really solved my problem.

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lost+found genesis
Let somebody correct me if I'am wrong.
lost+found directory is standard for some unix/linux filesystems. All ext(s) 2, 3 and 4 contains it by default.
The operating system collects unidentified, broken files and its parts inside of l+f dir.
No one of these junks is used by running system.
So - you can look in l+f for some lost, missing files. If you don't miss for any (who knows it better?) then you don't need l+f content.