How do I point certain directory to /dev/null?

Question

I am running CentOS with cPanel, which creates a custom log directory and writes the logs there. The result is that the IO for the hard disk goes sky high.

If I do lsof I got:

hostsite.com

httpd      2383    nobody 3779w   REG  253,0         0  422463 /usr/local/apache/domlogs/mygamecardotcobnao.super                  hostsite.com-bytes_log
httpd      2383    nobody 3780w   REG  253,0      5265  420994 /usr/local/apache/domlogs/myfreefreedatixuua.super                  hostsite.com
httpd      2383    nobody 3781w   REG  253,0        36  422464 /usr/local/apache/domlogs/myfreefreedatixuua.super                  hostsite.com-bytes_log
httpd      2383    nobody 3782w   REG  253,0      3101  415849 /usr/local/apache/domlogs/myfreedatingfrekeuo.supe                  rhostsite.com
httpd      2383    nobody 3783w   REG  253,0        72  422465 /usr/local/apache/domlogs/myfreedatingfrekeuo.supe                  rhostsite.com-bytes_log
httpd      2383    nobody 3784w   REG  253,0       672  419338 /usr/local/apache/domlogs/myfreedatingblogsxgo.sup                  erhostsite.com
httpd      2383    nobody 3785w   REG  253,0         0  422466 /usr/local/apache/domlogs/myfreedatingblogsxgo.sup

Disabling this domlog is impossible because there are tons of those lines automatically generated.

I just want to point /usr/local/apache/domlogs/ to /dev/null. Can that be done?

Does it stop working if you remove permissions to that directory? (chmod 0 /usr/local/apache/domlogs/) or remove it altogether? Can you create those log files beforehand as symlinks to /dev/null? — Stéphane Chazelas, Dec 28 '12 at 01:41
No idea if it's stable but nullfs might be something for you: https://github.com/xrgtn/nullfs — ThiefMaster, Jan 04 '13 at 22:07

score 7 · Accepted Answer · answered Dec 28 '12 at 01:01

7

If you can afford some RAM, you can set up a RAM disk and let your logs go there:

mount -t tmpfs -o size=200M none /usr/local/apache/domlogs

Additionally, you should setup logrotate to rotate the logs every minute/hour/day/night/week/* and delete the old logs. This is not exactly what you want, but it should fix your problem as RAM I/O won't slow down your disks.

answered Dec 28 '12 at 01:01

mgabriel

361

This would be the best solution IMHO. – Renan Dec 28 '12 at 02:24
I have huge ram. I simply do not need the log though. Interesting. – user4951 Dec 28 '12 at 04:50
what would be the command to mount /usr/local/apache/domlogs to /dev/null instead? – user4951 Dec 28 '12 at 04:56

Renan · Answer 2 · 2012-12-28T02:25:12.913

2

A not-very-good solution (the ones proposed in other answers are much better), but you could remove the directory and them symlink it to /dev/null. But then, applications might start failing when they try to write to that directory and find that it's not actually a directory.

edited Dec 28 '12 at 02:25

answered Dec 27 '12 at 23:47

Renan

17,136

how to do so? I really don't need this domlogs and there is no easy way for cpanel to just don't write those log. – user4951 Dec 27 '12 at 23:53
Delete the directory (e.g. rm -rf /usr/local/apache/domlogs) and replace it by a symlink (ln -s /dev/null /usr/local/apache/domlogs). – Renan Dec 27 '12 at 23:58

score 1 · Answer 3 · answered Dec 28 '12 at 00:34

1

No, you can not, because /dev/null is a file ( devnode actually ), not a directory. You can not create files inside it. You will need to configure the app not to bother creating these logs.

answered Dec 28 '12 at 00:34

psusi

17,303

How do I point certain directory to /dev/null?

3 Answers3