Re: Raid 10 Problems?
From: Bill Davidsen
Date: Tue Mar 06 2007 - 11:46:39 EST
Marc Perkel wrote:
--- Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> wrote:
On Mar 4 2007 19:17, Marc Perkel wrote:
Thanks - because of your suggestion I had found the
instructions. But you have some interesting options
set.
-N nicearray -b internal -e 1.0
Are these important?
-N? What's in a name? I suppose, it's not so
important.
(Arrays are identified by their UUID anyway. But
maybe
udev can do something with the name someday as it
does
today with /dev/disk/*.)
Not worth starting over for.
-b internal -- seems like a good idea to speed up
resynchronization.
I'm trying to figure out what the default is.
-e 1.0 -- I wonder why the new superblock format
is
not default in mdadm (0.90 is still used).
Looks interesting for big arrays but not sure it's
worth starting over for. Trying to get through a 2
hour sync using 4 500gb sata 2 drives.
That's exactly why you want the bitmap. Fortunately you can add it after
the array is created. Now the bad news, you should read and understand
the meaning of the "far" layout. Part of the information is in the mdadm
man page under -p, some in the md man page. Use of "far" layout will
effect the performance of the array, the balance of read vs. write
performance, and (maybe) the reliability.
Two hours is a pretty short time to invest if you find that you have
your layout wrong and would be better off for the life of the array with
some other data layout. And the time to do the reading is worth if if
you wind up convinced that the default settings are fine for you.
--
Bill Davidsen <davidsen@xxxxxxx>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot
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