[linux-lvm] q: BLOCK_SIZE

[Andreas Dilger]

Michael writes:
> Little question that I already posted here a long time ago.
> What drawbacks can suffer if one changes BLOCK_SIZE in
> include/linux/lvm.h from 1024 (or 4096 on S/390) to 512?

On S/390 it would appear that the DASD block devices have a 4096
byte sector size.  However, on most other systems there is only
a 512 byte sector size, so I don't see any reason there would
be problems with BLOCK_SIZE = 512.

I think Andrea Arcangeli was complaining about this as well.

> This is about using lvm with rawio -- on 2.2, rawio wan't
> work with i/o size be not a multiple of blocksize, while
> on 2.4 it works.  Or at least this was on Dec-2000.
> Oh yes, this is about 2.2 kernel and lvm-0.9.

If it works for you at 512 bytes, leave it then.  Maybe Heinz
will let us know why it is set to 1024 bytes.

Cheers, Andreas
-- 
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert