<br><br><div class="gmail_quote">On Tue, Jan 13, 2009 at 3:58 PM, Michael D. O'Brien <span dir="ltr"><<a href="mailto:obrienmd@gmail.com">obrienmd@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br><div class="gmail_quote"><div><div></div><div class="Wj3C7c"><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="gmail_quote">
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On Tue, Jan 13, 2009 at 3:13 PM, Michael D. O'Brien <span dir="ltr"><<a href="mailto:obrienmd@gmail.com" target="_blank">obrienmd@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
In the last week I've upgraded my back and frontends to Ubuntu 8.10 and the newest myth-fixes. Last night, I noticed that the show I was viewing was pausing every few seconds, rendering it nearly unwatchable. I knew the backend was recording a few other shows and the frontends hadn't shown this behavior while the backend was idle earlier that day, so I did some looking around:<br>
<br>-top on the backend and frontend showed plently of available memory and idle cpu<br>-it's not a network issue, the maximum usage in iftop on the frontend looked to be about 12mbps (out of 100) and on the backend around 30mbps (out of 1000), due to recording 2 shows off our hdhomerun while I was watching this other show.<br>
-on the backend, top shows iowait hovering around 20-40%, which isn't bad and was common while recording 3 HD shows and watching 1<br>-on the backend, iostat -xk 1 shows something interesting: my raid5 array participants are all being used, but it seems that two of the drives hover around 10% usage, while one is constantly pegged at 100% usage. Is this normal behavior in iostat -xk for a raid5 array? it seems odd to me.<br>
<br>My backend is a C2D e6320 with 3GB of ram running Ubuntu 8.10 and the newest myth-fixes. Myth records to a raid5 array of 3x750gb drives with a 1.5tb xfs file system on top. It's connected to the network via 1000bT ethernet.<br>
<br>My frontends are AMD x2 4000+ with 1GB of ram running Ubuntu 8.10 and the newest myth-fixes. They are connected to the network via 100bTX ethernet.<br><br>Thoughts? I'm intrigued by the what seems to be strange iostat results on the backend...</blockquote>
</div></div><div><br>smartd?</div></div></blockquote><br></div></div>SMART values look fine for all drives. Also checked xfs file system, it's clean and not fragged at all.</div></blockquote><div><br>Actually, I was referring to whether smartd may have been running a check on the disk during that high I/O period.<br>
<br>Kevin</div></div><br>