I'm working on 2 systems that are mainly for running vdr. I've had these
running somewhat for awhile with raid. But a couple nights ago as I was
quitting for the night, I noticed one of the computers drive light
staying on. I had just made some changes to xine and didn't know if
something had crashed. Turned on the TV and found the video was freezing
for 10-20secs every 10-20secs. Logging in using putty and winscp I found
it very sluggish to respond.Starting top I found it was doing the
regular array check/resync. The process was using about 64% cpu and cpu
was staying at idle speed (1000Mhz). These computers use Athlon64 x2
cpu's. A problem with the AN2 socket systems is that when the cpu is
throttled back, it also slows the bus. This has been found to be a
problem on boards with integrated graphics when using nvidia's vdpau for
hardware video decoding because they use system ram. The fix is to set
the lower speed limit to 1800Mhz and/or change the up_threshold to ~50%
. However, I am using PCIe video cards and so up till now have not had a
problem.
I stopped vdr, but putty and winscp where still sluggish. This tells me
that it is loading the bus so much that both the video card and the
network is effected. it would also effect any tuner cards interfering
with any recording that may be going on at the time. I change the
up_threshold from the default 95% to 50% which should kick the speed up
when it's syncing. But I'm not sure that will be enough. Could there be
some other setting that is wrong raising the priority of the process?
Seems like this would be a problem for any system having raid
maintenance bring the system to its knees. The eta to finish was 75 minutes.
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