Re: Hi! Strange issue with LSR -- bitmaps hadn't been used during 2 of 3 RAIDs resync

On 26 June 2012 14:18, NeilBrown [off-list ref] wrote:

On Wed, 20 Jun 2012 10:49:32 +0800 Igor M Podlesny [off-list ref]
wrote:

[…]

quoted

   Here it is: http://pastie.org/4118133

This doesn't appear to show the "start to end" that I suggested, just 10% to
30%, but it does suggest that the bitmap isn't speeding things up at all, at
least for that part of the array... That is assuming you are talking about

   Well, I decided that's enough to be "pasted", but anyway, I can
assure you — it took ~ 1 hour, as it was estimated, so yeah — no use
of bitmap. For sure.

md124.  I note that md125 doesn't have a bitmap.  Is that what you are
referring to?

   Yeah, md125 is legacy RAID which is not being in use for a long
time, it's just hanging around till re-layout happens.

The next thing to do would be to look at the bitmap immediately after reboot
to see how many bits are set.  Maybe lots are set for some reason.

quoted

   — 3.4.2-rt10 went suspend ok for 2 times, the 3rd it didn't.
Reboot, resync, no bitmaps use.

   And, BTW, it's rather slow in despite of having max. stripe_cache_size set.

A larger stripe cache isn't going to affect resync speed much (I think).
50MB/sec on each drive seems fairly good to me.  What were you expecting?

   I see, thanks.

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