[mrtg] please help with detail graph issue

[Steve Shipway]

> We have an old MRTG server running MRTG-RRD and upgraded to a new
> server. When we did the upgrade we installed the latest MRTG, RRD and we
> also used Routers2.cgi. We were experiencing the same graphing issue.
...
> that the main page always works but the detail page is hit or miss. One
> time it will show you all the graphs the next time one or maybe two and
> then the next time no graphs just the written statistics.

With routers2, the temporary graphs will normally be stored under <webroot>/graphs -- the actual path is defined in the routers2.conf file.  The Workdir: is where the .rrd files are kept, and this should not be under the webroot for security reasons.

This directory should be accessible to all, and preferably with cache expiry options as stated in the documentation, plus a regular cleanup process if possible.

I would suggest you try checking the following:

1) Check the date and time synch on your web server and clients.  This can cause problems with cookie and cache expiry making broken images.
2) Check permissions on the /graphs directory, to make sure thet it is accessible (make sure there is read permission as well as execute if this is a unix web server)
3) Check the expiry rules (.htaccess file) if you have any.  Make sure they are not expiring too soon.
4) Check you do not have a disk full, or quota problem, on the filesystem containing the /graphs directory.
5) Are you using routers2 with the clustered distributed front-end option?  If so, then this sort of thing can be caused by the members of he web frontend cluster having incorrect time synchronisation or one of them having a disk full on the disk containing the graphs directory.

Steve