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dm-raid1 improvements

dm-raid1 improvements

Posted Apr 20, 2008 17:59 UTC (Sun) by sbergman27 (subscriber, #10767)
In reply to: dm-raid1 improvements by nix
Parent article: Stable kernel 2.6.25 released

Well, I am using the mapper.  And if I dd from the /dev/mapper/VolGroupxx/LogVolxx/ to
/dev/null and then do the same with /dev/sdax, which is the first member of the raid1 array, I
get about 61MB/sec in both cases.  So I guess I'm not getting read balancing in F8.  Or, come
to think of it, is the read balancing that fine-grained?  I recall somebody telling me, a
while back, that it only balanced reads from different processes, and not from the same
process, or something like that.


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dm-raid1 improvements

Posted Apr 20, 2008 18:21 UTC (Sun) by nix (subscriber, #2304) [Link]

I can't imagine dm could tell which process was originating the request, 
even if it wanted to. It's all one by that point.

dm-raid1 improvements

Posted Apr 20, 2008 18:44 UTC (Sun) by sbergman27 (subscriber, #10767) [Link]

Seemed odd to me, too.  Another odd thing is that this kernel release, which I had not really
thought was anything all that special, actually has not one, but at least two bombshell
features.  How did I miss the loud outcry which surely occurred when read balance support in
raid1 was lost?  And why have both its return, and the new TASK_KILLABLE functionality gotten
so little notice?

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