How to Free Inode Usage?

问题:

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?

回答1:

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_$$ | sort -n
rm -f /tmp/count_em_$$

回答2:

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.

回答3:

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% /

回答4:

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.

回答5:

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)

回答6:

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)

回答7:

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

回答8:

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.

回答9:

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

回答10:

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.

回答11:

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.