Fix for "cannot schedule recording" guid

Started by Shane, February 17, 2006, 12:04:54 PM

Previous topic - Next topic

Shane

Hi all,

I'm pretty excited to post this as this issue has caused me problems for a while, popping up for no apparent reason. I've previously fixed it by sheduling a system restart twice a week, but with this no more!

The error message given is:
"Cannot schedule recording because guide data cannot be accessed"

Peter Rosser, one of the Developers at Microsoft has posted the following at his blog:

QuoteWe have been getting reports about Guide problems from DVB users across Europe and the world, hopefully in time for the next Rollup release (external date not yet announced, but should be late Q1 to early Q2).  The problem typically manifests itself when scheduling many shows to record, but can occur anytime.  Without a code fix, you cannot work around the issue cleanly/easily, but closing the shell (Media Center UI) and restarting the "Media Center Scheduler Service" (ehsched) will reset the state of the machine.

We root-caused the problem to an unusual memory management problem in how we deal with the Guide data.  For performance reasons, we temporarily increase certain buffer sizes during a Guide download, and decrease them again later.  There is a timing issue with garbage collection events in some situations, though, that can cause the decrease to not take effect "in time", thus keeping the buffer sizes large.  This does not actually reduce the amount of real memory used, but it does exhaust the virtual address space eventually.  You can observe the behavior using SysInternals' Process Explorer by adding the "Virtual Size" column (under the Process Performance tab) and observing its value for ehrec.exe.

With better knowledge of the cause, though, comes a better workaround than "gun ehshell.exe and restart ehsched when it happens".  Until the fix comes out, the best thing to do to prevent this problem from occurring is probably to set up a Scheduled Task to do those things for you at a predictable time.

More info on what you need to do is available at this posting on his site:
http://blogs.msdn.com/peterrosser/archive/2006/02/15/DvbGuideProblem.aspx

Regards,
Shane.
Shuttle SB83G5M (P4 630 nVidia 6600) running Vista Premium with:
Hauppauge Nova-T 500 MCE Tuner|Ice TV Guide|PIMP|Buffalo LinkStation HD-H160LAN & HD-HG300LAN|Xbox 360 MCE