How to Free Inode Usage?

I have a disk drive where the inode usage is 100% (using df -i command). However after deleting files substantially, the usage remains 100%.

What's the correct way to do it then?

How is it possible that a disk drive with less disk space usage can have higher Inode usage than disk drive with higher disk space usage?

Is it possible if I zip lot of files would that reduce the used inode count?

If you are very unlucky you have used about 100% of all inodes and can't create the scipt. You can check this with df -ih.

Then this bash command may help you:

sudo find . -xdev -type f | cut -d "/" -f 2 | sort | uniq -c | sort -n

And yes, this will take time, but you can locate the directory with the most files.

It's quite easy for a disk to have a large number of inodes used even if the disk is not very full.

An inode is allocated to a file so, if you have gazillions of files, all 1 byte each, you'll run out of inodes long before you run out of disk.

It's also possible that deleting files will not reduce the inode count if the files have multiple hard links. As I said, inodes belong to the file, not the directory entry. If a file has two directory entries linked to it, deleting one will not free the inode.

Additionally, you can delete a directory entry but, if a running process still has the file open, the inode won't be freed.

My initial advice would be to delete all the files you can, then reboot the box to ensure no processes are left holding the files open.

If you do that and you still have a problem, let us know.

By the way, if you're looking for the directories that contain lots of files, this script may help:

#!/bin/bash
# count_em - count files in all subdirectories under current directory.
echo 'echo $(ls -a "$1" | wc -l) $1' >/tmp/count_em_$$
chmod 700 /tmp/count_em_$$
find . -mount -type d -print0 | xargs -0 -n1 /tmp/count_em_$$ | sort -n
rm -f /tmp/count_em_$$

My situation was that I was out of inodes and I had already deleted about everything I could.

$ df -i
Filesystem     Inodes  IUsed  IFree IUse% Mounted on
/dev/sda1      942080 507361     11  100% /

I am on an ubuntu 12.04LTS and could not remove the old linux kernels which took up about 400,000 inodes because apt was broken because of a missing package. And I couldn't install the new package because I was out of inodes so I was stuck.

I ended up deleting a few old linux kernels by hand to free up about 10,000 inodes

$ sudo rm -rf /usr/src/linux-headers-3.2.0-2*

This was enough to then let me install the missing package and fix my apt

$ sudo apt-get install linux-headers-3.2.0-76-generic-pae

and then remove the rest of the old linux kernels with apt

$ sudo apt-get autoremove

things are much better now

$ df -i
Filesystem     Inodes  IUsed  IFree IUse% Mounted on
/dev/sda1      942080 507361 434719   54% /

My solution:

Try to find if this is an inodes problem with:

df -ih

Try to find root folders with large inodes count:

for i in /*; do echo $i; find $i |wc -l; done

Try to find specific folders:

for i in /src/*; do echo $i; find $i |wc -l; done

If this is linux headers, try to remove oldest with:

sudo apt-get autoremove linux-headers-3.13.0-24

Personally I moved them to a mounted folder (because for me last command failed) and installed the latest with:

sudo apt-get autoremove -f

This solved my problem.

I had the same problem, fixed it by removing the directory sessions of php

rm -rf /var/lib/php/sessions/

It may be under /var/lib/php5 if you are using a older php version.

Recreate it with the following permission

mkdir /var/lib/php/sessions/ && chmod 1733 /var/lib/php/sessions/

Permission by default for directory on Debian showed drwx-wx-wt (1733)

We experienced this on a HostGator account (who place inode limits on all their hosting) following a spam attack. It left vast numbers of queue records in /root/.cpanel/comet. If this happens and you find you have no free inodes, you can run this cpanel utility through shell:

/usr/local/cpanel/bin/purge_dead_comet_files

You can use RSYNC to DELETE the large number of files

rsync -a --delete blanktest/ test/

Create blanktest folder with 0 files in it and command will sync your test folders with large number of files(I have deleted nearly 5M files using this method).

Thanks to http://www.slashroot.in/which-is-the-fastest-method-to-delete-files-in-linux

Late answer: In my case, it was my session files under

/var/lib/php/sessions

that were using Inodes.
I was even unable to open my crontab or making a new directory let alone triggering the deletion operation. Since I use PHP, we have this guide where I copied the code from example 1 and set up a cronjob to execute that part of the code.

<?php
// Note: This script should be executed by the same user of web server 
process.

// Need active session to initialize session data storage access.
session_start();

// Executes GC immediately
session_gc();

// Clean up session ID created by session_gc()
session_destroy();
?>

If you're wondering how did I manage to open my crontab, then well, I deleted some sessions manually through CLI.

Hope this helps!

eaccelerator could be causing the problem since it compiles PHP into blocks...I've had this problem with an Amazon AWS server on a site with heavy load. Free up Inodes by deleting the eaccelerator cache in /var/cache/eaccelerator if you continue to have issues.

rm -rf /var/cache/eaccelerator/*

(or whatever your cache dir)

We faced similar issue recently, In case if a process refers to a deleted file, the Inode shall not be released, so you need to check lsof /, and kill/ restart the process will release the inodes.

Correct me if am wrong here.

As told before, filesystem may run out of inodes, if there are a lot of small files. I have provided some means to find directories that contain most files [here][1].

[1]: https://stackoverflow.com/a/39379847/4414935 "my answer to another question"

In one of the above answers it was suggested that sessions was the cause of running out of inodes and in our case that is exactly what it was. To add to that answer though I would suggest to check the php.ini file and ensure session.gc_probability = 1 also session.gc_divisor = 1000 and session.gc_maxlifetime = 1440. In our case session.gc_probability was equal to 0 and caused this issue.

this article saved my day: https://bewilderedoctothorpe.net/2018/12/21/out-of-inodes/

find . -maxdepth 1 -type d | grep -v '^\.$' | xargs -n 1 -i{} find {} -xdev -type f | cut -d "/" -f 2 | uniq -c | sort -n

On Raspberry Pi I had a problem with /var/cache/fontconfig dir with large number of files. Removing it took more than hour. And of couse rm -rf *.cache* raised Argument list too long error. I used below one

find . -name '*.cache*' | xargs rm -f

firstly, get the inode storage usage:

df -i

The next step is to find those files. For that, we can use a small script that will list the directories and the number of files on them.

for i in /*; do echo $i; find $i |wc -l; done

From the output, you can see the directory which uses a large number of files, then repeat this script for that directory like below. Repeat it until you see the suspected directory.

for i in /home/*; do echo $i; find $i |wc -l; done

When you find the suspected directory with large number of unwanted files. Just delete the unwanted files on that directory and free up some inode space by the following the command.

rm -rf /home/bad_user/directory_with_lots_of_empty_files

You have successfully solved the problem. Check the inode usage now with the df -i command again, you can see the difference like this.

df -i

you could see this info

for i in /var/run/*;do echo -n "$i "; find $i| wc -l;done | column -t

Many answers to this one so far and all of the above seem concrete. I think you'll be safe by using stat as you go along, but OS depending, you may get some inode errors creep up on you. So implementing your own stat call functionality using 64bit to avoid any overflow issues seems fairly compatible.

If you use docker, remove all images. They used many space....

Stop all containers

docker stop $(docker ps -a -q)

Delete all containers

docker rm $(docker ps -a -q)

Delete all images

docker rmi $(docker images -q)

Works to me