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Subject: chunk-size for raid1 personality
Date:   Thu, 3 Dec 1998 19:15:46 -0500
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Hi,

I've been reading the source code, and I've come to the following
conclusions about the chunk-size for a raid1 device.

The chunk size:

(1) must be non-zero
(2) must be a multiple of four
(3) must be a multiple of the system page size
(4) must be less than MAX_CHUNK_SIZE (4096*1024 on my system)

and has no effect for raid1 devices. (Other than the device size is rounded
down to the nearest multiple of the chunk size, so a really large chunk-size
could cost you some space.)

So, the example value of 128 in the raidtools-0.90/raidtab.samle file should
work just fine for about everybody.

 - David Harris
   Principal Engineer, DRH Internet Services

==================================================================

from md.txt
-----------
     chunk size
        is for raid-0 and raid-1 only. Set the chunk size as PAGE_SIZE << n.

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