tail: inotify cannot be used, reverting to polling: Too many open files
Solution 1
This was solved for me by following the instructions on http://peter-butkovic.blogspot.com/2013/08/tail-inotify-resources-exhausted.html
Permanent solution (preserved across restarts) Adding line:
fs.inotify.max_user_watches=1048576
to:
/etc/sysctl.conf
fixed the limit value permanently (even between restarts).
then do a
sysctl -p
Solution 2
I think that answer is not complete (it doesn't say anything about the maximum limit of files open on the system).
There are two limits regarding the maximum number of open files:
-
Maximum limit of files open per process.
- You can see which is the value of this limit using:
ulimit -n
- You can change this limit using:
ulimit -n new_limit_number
-
Here is a command to get the top 10 processes having many files open:
lsof | awk '{ print $2; }' | sort -rn | uniq -c | sort -rn | head
- You can see which is the value of this limit using:
-
Maximum limit of files open per system.
- You can see which is the value of this limit using:
cat /proc/sys/fs/file-max
- You can change this limit using:
echo new_limit_number > /proc/sys/fs/file-max
- Count all open file handles:
lsof | wc -l
- You can see which is the value of this limit using:
Solution 3
sysctl fs.inotify.max_user_instances
would get limit per user for inotify
.
I experienced it, and all limit system wide were high enough, but setting by user are usually relatively low by default, you can increase it in sysctl.conf
and reload it whit sysctl -p
.
Solution 4
Most likely, you've run out of your inotify
watches. Probably, you're running some file synchronization tools(eg. Dropbox) in background?
In Linux, the internal implementation of tail -f
command uses the inotify
mechanism by default, so as to monitor file changes. If you've run out of all the inotify
watches(8192 by default), then inotify -f
have to switch to polling to detect changes to that file.
Of course, you can modify the maximum number of inotify
watches.
reference:
http://www.quora.com/How-is-tail-f-implemented
http://peter-butkovic.blogspot.com/2013/08/tail-inotify-resources-exhausted.html
https://serverfault.com/questions/510708/tail-inotify-cannot-be-used-reverting-to-polling-too-many-open-files
Solution 5
Run
ps aux | grep tail
to check if too many tail command running, such as a spawn by crontab.
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gbag
Updated on September 18, 2022Comments
-
gbag over 1 year
When I try to
tail -f catalina.out
, I get the error:tail: inotify cannot be used, reverting to polling: Too many open files
I tried the answer in this post: Too many open files - how to find the culprit
lsof | awk '{ print $2; }' | sort -rn | uniq -c | sort -rn | head
When I ran the above command, the output was
17 6115 13 6413 10 6417 10 6415 9 6418 9 6416 9 6414 8 6419 4 9 4 8
I don't see any process having 1024 files open. Isn't the number of files open 17,13,10,10,9? Or am I understanding it wrong? And all these were bash,sshd,apache2, tomcat had number 4.
I also did
lsof | grep tail | wc -l
which returned20
. These numbers aren't huge, so why doestail -f catalina.out
fail? -
Alexander Mills over 7 yearsha this actually worked, tailing way too many files
-
Ruslan Stelmachenko over 6 yearsIncreasing file descriptors doesn't help me. My
tail
message was slightly different:tail: inotify resources exhausted
. This answer helped me. You can also usesudo sysctl -w fs.inotify.max_user_watches=1048576 && sysctl -p
to test if it helps without permanently modifying it. This post also helps nefaria.com/2014/08/tail-inotify-resources-exhausted -
Christia almost 6 yearsHow do I translate the data? Can you explain what each piece of information means and what to do about it? For example:
root 20161 0.0 0.0 11132 1044 pts/0 S+ 17:27 0:00 grep tail
-
tangxinfa over 5 yearsIt is a problem only if TOO MANY processes matched, the line matched contain "grep" is generated by the command itself. Please use "pgrep tail" command instead.