Subject: Re: Contraint to Blksize 512? 
To: Steve Lord <lord@sgi.com>
Cc: linux-xfs@oss.sgi.com
Message-ID: <OFC80C900A.5B01308A-ONC1256A79.0051271F@de.ibm.com>
From: "Holger Smolinski" <HSmolinski@de.ibm.com>
Date: Thu, 28 Jun 2001 16:49:13 +0200
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Sender: owner-linux-xfs@oss.sgi.com
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>> Hello,
>> I tried to use XFS with devices of sector sizes larger than 512 Byte and
>> failed.
>> Apparently there are dependencies to a fixed blocksize of 512 Byte all
over
>> the code of XFS.
>> Are these contraints unavoidable by the design of XFS or could you
imagine
>> running an XFS e.g. on a device with 4k blocksize and what needs to be
done
>> to the code in order to do so?
>Yes, unfortunately XFS is built around assumptions about 512 byte block
>sizes. There was an internal project to clean this up which was shelved
>a while back, I will ask around and see if the code still exists. I
>think this would end up with an incompatible on disk format, given that
>some structures would change size, but I think that would be an acceptable
>solution for devices with a larger block size.

For sure we would have incompatible layouts between XFS(512) and XFS(4k).
I'd imagine sth like replacing any 512 in the XFS code by blksize(device)
or blksize(xfs-type) rsp.
Do you see any design obstacles in doing so?

Gruesse / Regards
        Dr. Holger Smolinski