[mythtv-users] Software RAID and ionice

Yeechang Lee ylee at pobox.com
Sat May 26 04:45:55 UTC 2007


David Rees <drees76 at gmail.com> says:
> Those values are 128MB buffer, 5MB max write and 0.25MB min write
> sizes. Those settings seem pretty sane to me, although I imagine that
> the amount of buffer you're willing to allocate is going to depend a
> good deal on the available memory in the machine and how many parallel
> writers you have.

I currently have four (up from the three I've discussed in the
previously-referenced posts on my setup and its ability to handle
super-demanding workloads), all high definition-capable.

> It's pretty straight forward. Just put a // in front of line 336 of
> ThreadedFileWriter.cpp which should correspond to a call to Sync().

Tried this today. When pushed to the limits in ways akin to the tests
I've previously written about, I found that the system seemed to
"lose" about 10 to 30 more seconds per recording than with line 336;
that is, a one-hour recording would often, not always, come out as
59:45 or 59:30 instead of 59:55. I've reverted to unpatched binaries
(with the above-mentioned TFW patch, of course, as well as other
patches I've long used) as I'm leaving on a trip tomorrow and want my
recordings in the meanwhile to occur within a proven environment.

-- 
Yeechang Lee <ylee at pobox.com> | +1 650 776 7763 | San Francisco CA US


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