On Thursday 12 January 2006 11:47, Johnathon Meichtry wrote: > > ----- Original Message ----- > > From: "Steve Adeff" <[EMAIL PROTECTED]> > > To: <[email protected]> > > Sent: Thursday, January 12, 2006 4:21 PM > > Subject: Re: [mythtv-users] Software RAID5 no improvement to > > transferspeed... > > > > Just to let you guys know, it was an SQL issue, I sent a new email, but > > changed the subject announcing it... I had my other machine (over 100bT) > > running the SQL db, once I moved it back to the local machine it plays back > > fine. > > > > thanks for the info though, some good info. > > > > Johnathon: I don't even notice 3% use by the RAID, I've seen %wa as high as > > 6%. I get load averges around 4 while watching HD and recording 2 shows. > > > > Ramses: great command! I need to store that to my repertoire. > > > > Hi Steve, > > Cool! > > On my modern 3.6GHZ server, cpu usage on raid is negligible - something > less than 1% but on much slower machines in the past I have seen it up > around 3% so the point I was trying to make was that it should never cause > the CPU to head up into the 90's under even the most extreme situation > unless of course there is some major a bug.
gotcha, well, I don't even notice it come up in top, so I'm happy =) > My IO waits are a different matter. If software RAID (RAID1) is in use and > server is busy, io waits (wa) never really exceed 10% but with my hardware > RAID5 array frequently I see it getting up to 40% io waits if it is really > busy. Its quite ironic as that is why I paid loads of money for it - my > bet is there is a bug in the controller firmware but the manufacturer > doesn't seem to be doing much about it at least the server performs well so > I don't bother myself too much over it. Ok, I've got only one RAID array, RAID 5, my db is currently on a non RAID UDMA5 ATA Seagate Barracuda 7200 drive (might move this to RAID5 for protection though). In top, my wa% is always at 0.0, with occasional jumps to 3.3 or 3.4 (this is with top's update speed set to .3). Right now I'm recording 2 HD shows and watching 1, recording 1 PBS show and watching 1 in fact, with load average: ~5.50 ~5.10 ~3.5 cpu ~90%us, 0.0% wa. and no visible visual or audio hiccup. Some of this is due to the xorg.conf changes I made, documented in another email to the list. > If your load averages are 0.40 then to me that is fine but if it is 4.00 > then that is not so good as most Unix pros would consider that to be an > overloaded CPU. Of course its all speculation and people interpret load > averages differently. I can understand, look at what top says my load averages are, sure I'm dong a lot but I'm not seeing anthing wrong with my playback as I watch a PBS HD stream. -- Steve _______________________________________________ mythtv-users mailing list [email protected] http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
