As its in test, it got stuck on our currently relatively unused “old” vmware environment (ESX 3). After initially going well it start to go wrong. We kept getting critical alerts that a server was up. Switching zenping to debug didn’t help either – it offered no new information and made the problem worse. As its open source I thought I’d take a look at the source, and hey presto I found the suspected problem. Stuck in an extra debug line, and confirmed it.

The problem – well it was an issue with the clock on the server caused by running under vmware , it was jumping about leading to negative rrt on pings. Funnily enough zenoss didn’t like. I’ll be submitting a bug so that it comes up with the slightly less cryptic error of Ip xxx.xxx.xxx.xx is up. To fix the problem, I had to specify the clocksource in the kernel options. See vmware KB 1006427 for details.

If you can’t fix this for some reason or can’t reboot server, for now you can put an event transform for status/ping in place to suppress them.

import re
 
match = re.search('ip (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?) is up', evt.message)
if match and evt.severity==5:
	evt._action = 'drop'

Please note: I’m assuming you still use the default theme. Things will be slightly different with other themes, but in general the same principal should apply.

In the file header.php remove media=”screen” from the following line:

<link rel="stylesheet" href="<?php bloginfo('stylesheet_url'); ?>" type="text/css" media="screen" />

In style.css, just before the line

/* Begin Typography & Colors */

Add

@media screen {

At the bottom of the file add the following line:

}
@media print {
    /* style sheet for print goes here */  
   #sidebar { display: none; }
}

Bingo no wasted paper from printing the side bar.

Ubuntu lists it as:

Zeroconf LIRC daemon using input event devices
This is a small LIRC-compatible daemon that reads from /dev/input/eventX
devices and sends the received keycodes to connecting LIRC clients. Inputlircd
needs no configuration, it uses the standardised names for the keycodes as
used by the kernel. Many USB remote controls that present HID devices, as well
as multimedia keyboards should work out of the box.

Why is this good, well I just install this package and well I get full remote support – once I’ve configured the applications, which is still a pain in the arse. Now if the applications could be written to work with the zeroconfig lirc with well zero config the world will be great (well ok less un-great).

Its now running on Debian for the next Cacti box (assuming it doesn’t have the gd bug).

What has helped with the new Cacti box is a combination of a few things – the new 1 min poller patch spreads I/O out better, and allows me to poll device which don’t do 64bit SNMP counters yet have gigabit ethernet ports every min, and leave everything else at 5 min. Improvements on plugins and a switch to cactid (a c version of the poller) has also really helped. The system now process ~400 hots in 35 seconds, dealing with ~4100 data sources and ~2200 rrd each min. Not bad.

There are a couple things that need improving however:
1) The threshold system now inspects data straight from the db before writing to the rrd files, which unfortunately causes the graphs in the email to be 1 cycle out of date (ie not show the data the emails about).
2) The Uptime+Threshold system host down email only works by patching files yourself at present when using cactid

As for ubuntu – either stop shipping cactid, or compile it again the correct version of the libraries. I’d much rather the package not be there than for it to not work, it gives people a bad impression.

Well I’ve done something about it (well at least on my blog) – I’ve changed my theme so that on browsers that supports css and media types the sidebar shouldn’t print out. Here’s how you can add this to you’re WordPress blog

1. Create a file print-style.css in the directory for you’re current theme with the following content
   .dontprint{ display: none; }
div#menu{ display: none; }
2. In wordpress, goto Presentation, Theme Editor and select the file Header
3. Just bellow the line setting the css style sheet – should be something like this :
   <style type="text/css" media="screen">
@import url( %lt;?php bloginfo('stylesheet_url'); ?> );
<style>

   add the lines
   <style type="text/css" media="print">
@import url(<?php bloginfo('template_directory'); ?>/style-print.css);
</style>
4. Hopefully this should be enough, but if the theme author hasn’t used the div’s in the sidebar file you may have to add this line <div id="menu"> to the top of the file and this line </div> to the bottom of the file

Anyway I have a fix for this now – simply call mostwanted using these two lines of php:
$mostwanted = new MostWanted;
$mostwanted->mostwanted(7, 30, true);

in replace of

MostWanted::mostwanted(7, 30, true);


Easy to fix – log on. Goto system > administration and set a default printer. Still you’d have though that when I only have one printer, and its the first printer I added it would be the default, by well default

The two tables moved are: snmp_counter64* and poller_output. Both these tables can afford to loose the data on restart – they hold data before it is moved into the rra and holds at most 5 mins worth of data (IE one cycle).

It also improves the situation if the server restarts as if data is left in the poller_output table it can push the the php poller over its memory limit and stop it working properly, so its a good idea to start with it empty.

Snmp_counter64 also needs emptying every now and again – as when you remove devices from cacti it does not get removed from here

The SQL code to achieve this is:

alter table cacti.snmp_counter64 engine=heap;
delete from cacti.poller_output;
ALTER TABLE cacti.poller_output MODIFY COLUMN output VARCHAR(255);
alter table cacti.poller_output engine=heap;


Warning
Some graphs may stop updating if the script used to generate data for the output more the 255 characters If you use MYSQL 5, then you can use something like VARCHAR(1024) instead.
This may cause data to be lost from the current run.

The server now copes pretty well. I haven’t tried anything new to it yet, but it generally appears to be working better then it has done for past couple of months. I would like to re do the disk structure, but for now this will do.

*This table is from a patch – most people won’t have this table.

Currently it has:
Hosts:354 Data-Sources:16943 RRDs Processed:8744

And has hit a limit with Disk i/o.

What I plan to do is: Move it onto a temp virtual server. Completely rebuild the old dell with two RAID 1 sets each on 2 disks – One for the RRA and one for the DB and see how it put up with that. The rebuild should help on the disk layout too – due to all the network changes and low disk space its likely the disk could have a few few frags.

If this doesn’t work and it still struggles, then I’ll use one of the various other spare dells (might have to be one without a raid card – so it’ll be software raid) and stick the database and possibly front end on it.

Once we have it stable again – I suppose I better look into a better way of coping with gigabit Ethernet cards in windows – currently we use the SnmpProxy2.pl hack – may just be a case of limiting it to Windows servers some how and not all 64bit Ethernet counters.

1. Ability to record digital TV as it is broadcasted without any additional compression
2. Ability to record more than one channel at once (preferably more than 2 some times)
3. Ability to overlap program recording where needed
4. Ability to Record radio stations
5. Backend front end system where by I can schedule/view/control the system from another computer
6. Ability to record one, two or more channels on any mux using one TV card (there’s no point having to use two TV cards to record channels on the same frequency.
7. Do this all in the background on a Debian Sarge (+ selected extra apt-get sources) System
8. A TV like interface I could fire up. I don’t mind if I can schedule or tune from this interface, but I’d like to see now and next info, change channel, pause live TV, hit record etc. I don’t need the ability to play games nor watch DVDs etc from it. I just want to channel surf sometimes or fire it up to watch something at the spur of a moment.
9. Scheduling would be nice, but as long as there some easy to use interface, I could plug in my current scheduling system

I currently use DVB Daemon + webdvbd (with some changes to give me a webinterface I can hook my scheduling program up to) + DigiGuide (via wine).

Its a bit of a bodge but gives me the most important features and is relatively stable (I do occasionally have scheduling issues even with two cards) and about >1% of the time I get a duff recording (picture drops out before the end or picture is too scrambled to watch), but this may be a driver issue.

What the current system lacks is clash detection (I can tell if I’m paying attention – but only for manually one time only added programs – they won’t appear if there’s a schedule problem). It also lacks a GUI and TV live interface. I can watch TV live but its not easy to do (I have to use dvbstream and mplayer – so can’t change channels using my remote). If I had more time, and more experience in this I may be tempted into making and interface, but I suspect MythTV will finally put up with the pain of breaking things and written in decent dvb support first.