[mythtv-users] Software RAID problems - theunspokenmythtvproblem?
adeffs at gmail.com
Thu Jan 12 18:15:33 UTC 2006
On Thursday 12 January 2006 12:59, James C. Dastrup wrote:
> >for what its worth, I am using 2 firewire "encoders" with a local 7
> >drive raid5. I am using latest ATrpms on FC3. kernel 2.6.12 smp.
> > I have had no problems with simultaneous HD recordings (even starting
> >at the same time), and the performance seems to be better than my old
> >2 drive LVM configuration.
> >No recording problems at all. I actually stopped getting glitches in
> >my HD records (part due to better RAID performance, part due to no
> >longer running commercial detection)
> Interesting you mentioned commercial detection as a source of problems.
> I, too, have _almost_ no more problems with HD recording anymore on
> my remote (NFS) software raid5 recordings, after I disabled
> commercial detection.
> I did notice a couple glitches during a show last night. I was a little
> surprised, because I haven't see any problems in days. Afterwards,
> I noticed my MRTG monitoring found a spike in CPU at the same time.
> I think it was my cron job of backing up the mysql database, which
> also backs it up to the same remote NFS server. Guess I should move
> it to a better time.
> So it seems that NFS storage and/or software raid, although it works,
> is just very sensitive to anything else going on. Hopefully I can
> make it a little more robust with gigabit links and maybe even
> hardware raid in the future. But like others, I'm just afraid of hardware
> raid in the long run, esp with the questionable ability to replace a
> failed HBA in the future with a compatible one.
u know, when I had my db running on a seperate machine over 100bT I found that
things slowed way down, nothing to do with the recordings drive speed!
Once I brought the db back to the backend machine that does the capturing and
storing everything went back to normal. I don't have commercial detection
enabled though. I wonder how much of the problems you two notice with
commercial detection has more to do with SQL not keeping up with all the
access its being asked of by Myth, or something along those lines?
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