Re: resync patch & Neil's recent patches

On Friday June 28, bo@sosnetwork.net wrote:

Neil,

quoted

quoted

I saw some bug fixes and improvement on this topic from
 http://marc.theaimsgroup.com/?l=linux-kernel&m=100876771508736&w=2

According to log file(from above infor), it cleaned up many things related
with RESYNC, and had
some bug fixes. He mentioned it goes to linux2.5.x.

I think we should have the same changes to Linux 2.4.x, don't you?

I don't think they were significant bugs.  resync works quite well in
2.4.  Well enough that I don't think it should be fiddled with too much.

If so which release should include them? Any problem to apply this patch
to my 2.4.5?

They won't work in 2.4 as they stand.  There were some major changes
to the block device layer in 2.5 and these patches require (and are
required by) these changes.

How about your patches(23+)? Can I apply them to my lINUX2.4.5?

No.  Same reason.  I might back-port the more significant ones, but
much of it was code-cleanliness rather than bug fixes.

I already use 100M  for speed _limit_min,  300M for speed _limit_max.
I could not notice a big difference from changing this values.

Q1: This value go back to the default at boot/reset,  Should I modify to
change this
       default value in "md.c"? By any config parameter?

Don't modify md.c.  Just echo a number to the /proc file in a boot
script.

Q2:  >hdparm -tT /dev/hdxx
          Timing buffer-cache reads: 52.24 MB/s
          Timing buffered disk reads: 24.43 MB/s

        The "resync" speed on the raid1 device with hdxx:  25.4MB/s.

        Do you think this speed is reasonable enough?

You couldn't ask for better.  This speed looks fine.

NeilBrown