[mythtv] [mythtv-commits] Ticket #1404: Invalid file error at

Bob Cottingham bobnvic at gmail.com
Mon Feb 27 14:42:34 UTC 2006


On 2/27/06, Chris Pinkham <cpinkham at bc2va.org> wrote:
> > I am using NFS v3 with sync writes, however, I do not have mysql or
> > nfs logging enabled. I went through my syslog and found that a cron
> > job kicked off at 12:30 to backup my mysql database on the MBE server
> > to the SBE server so I suspect that is the culprit.  Could a 23MB file
> > (my mythconverg database in gzip) transfer between the machines at the
> > wrong time cause this problem?
>
> Shouldn't, I have User Jobs that copy recordings around between
> filesystems as well as a nightly backup cron that backs up parts of my
> fileserver and they doesn't seem to kill my system.
>
> > If I follow you right, the slave backend got stuck waiting too long in
> > SetNextRecording() due to network traffic since whether it was writing
> > to the database or the nfs server it was still going across the
> > network which was busy transferring the 24MB file.  If transfer
>
> Well, since the cron that was running was a database backup, odds are it
> was probably the recordedmarkup table being locked so the recorder
> couldn't write out the rest of the seektable information to the database.
>
> > happens at any other time I suppose it may just cause some prebuffer
> > pauses that it can recover from?  I changed the time for the cron job
> > to 4:40am so that it will not likely occur at the time of a file
> > change again. I am going to leave the FE watching livetv all night to
> > see what happens at 4:40am.  Since I frequently copy 1GB files across
>
> You might get (un)lucky and it won't occur, it could just be the timing
> between when the program changed and when the cron was backing up a
> certain table (probably recordedmarkup since it's the largest table in
> the database), so it might not happen at 4:40am.
>
Your analysis makes a lot of sense.  Unfortunately, mythfrontend
crashed for some mysterious reason at 1:21am so I never saw what would
happen when the database backup occurred at 4:40am.  I wasn't running
it under gdb at the time so I don't have a backtrace and the logs
don't show anything - the frontend log just ends with the video
playing and mythfrontend is no longer running on the system.  The
backend at that point goes to StopLiveTV(void) and seems fine.  I'll
try watching LiveTV today while backing up the database and
transferring files and see what happens.

Thanks,
Bob C


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