APLawrence.com -  Resources for Unix and Linux Systems, Bloggers and the self-employed

Syslogd MARK option

© Tony Lawrence, aplawrence.com

Syslog can be run with a -m " option that just writes "- MARK --" at whatever intervals you specify. The purpose is to provide reassurance that syslogd is listening and doing its job even if it has nothing else to do right now.

I've had people worried by their seeing MARK in logs and not knowing why it was there, but until this thread I'd never seen anyone wondering why it WASN'T there. The reason is that syslogd doesn't bother to write a mark if something else cause it to write a log entry during the interval you specified. After all, the point of -m is to know that syslogd is alive and working, so why write a special mark if it just did real work? That's apparently the attitude of whoever wrote it, and it isn't entirely unreasonable, though as someone mentioned in this thread, it probably should be noted in the documentation.

So - if you are seeing "MARK, that's normal. Most systems are set up to do that. It lets you know that syslog has been doing its job, it isn't dead, there's just nothing to do right now. If you are NOT seeing it, but are seeing regular activity from other sources, that's normal too - don't worry about it.

Other Syslog issues

Another syslog issue that comes up now and then is syslog NOT writing to a log after you've told it to do so in /etc/syslog.conf. That's usually because you forgot to create the file; "man syslog" specifically says "For security reasons, syslogd will not append to log files that do not exist; therefore, they must be created manually before running syslogd.".

"ttloop: peer died" could mean someone is scanning for open ports.

Entries complaining about passwords mean someone has mistyped a password or is trying to guess one. Back in the days of dumb terminals, you'd see this when someone left a book lying on a keyboard.

(OLDER)    <- More Stuff -> (NEWER)    (NEWEST)   

Printer Friendly Version

-> -> Syslogd MARK option

1 comment

More Articles by

Find me on Google+

Tony Lawrence

Click here to add your comments
- no registration needed!

"Syslog can be run with a -m " option that just writes "- MARK --" at whatever intervals you specify. The purpose is to provide reassurance that syslogd is listening and doing its job even if it has nothing else to do right now."

Of course, you could look at ps -ef | grep syslogd to see if it is alive. &lt;Smile&gt; If the server is running any Internet-style services (e.g., named, sendmail, etc.) log entries are going to appear sooner or later.


Sun Jun 28 09:18:39 2009: 6553   anonymous

Thanks, Tony!
I have just wondered why the MARKs appear in my syslog rather irregularly; your blog was the first hit returned by Google. Indeed, it should be documented, under the description of -m flag.

Don't miss responses! Subscribe to Comments by RSS or by Email

Click here to add your comments

If you want a picture to show with your comment, go get a Gravatar
Kerio Samepage

Have you tried Searching this site?

Unix/Linux/Mac OS X support by phone, email or on-site: Support Rates

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us

Jump to Comments

Many of the products and books I review are things I purchased for my own use. Some were given to me specifically for the purpose of reviewing them. I resell or can earn commissions from the sale of some of these items. Links within these pages may be affiliate links that pay me for referring you to them. That's mostly insignificant amounts of money; whenever it is not I have made my relationship plain. I also may own stock in companies mentioned here. If you have any question, please do feel free to contact me.

I am a Kerio reseller. Articles here related to Kerio products reflect my honest opinion, but I do have an obvious interest in selling those products also.

Specific links that take you to pages that allow you to purchase the item I reviewed are very likely to pay me a commission. Many of the books I review were given to me by the publishers specifically for the purpose of writing a review. These gifts and referral fees do not affect my opinions; I often give bad reviews anyway.

We use Google third-party advertising companies to serve ads when you visit our website. These companies may use information (not including your name, address, email address, or telephone number) about your visits to this and other websites in order to provide advertisements about goods and services of interest to you. If you would like more information about this practice and to know your choices about not having this information used by these companies, click here.

This post tagged: