[linux-lvm] Re: [PATCH] 64 bit scsi read/write

[Juan Quintela]

>>>>> "chris" == Chris Wedgwood <cw at f00f.org> writes:

chris> On Sat, Jul 14, 2001 at 11:05:36PM -0700, John Alvord wrote:
chris> In the IBM solution to this (1977-78, VM/CMS) the critical data was
chris> written at the begining and the end of the block. If the two data items
chris> didn't match then the block was rejected.

chris> Neat.


chris> Simple and effective.  Presumably you can also checksum the block, and
chris> check that.

There is the rumor (I can't confirm that), that you need checksums,
that some disks are able to write well the beginning & the end of the
sector and put garbage in the middle in the case of problems.  I
have never been able to reproduce that errors, but ....

Later, Juan.


-- 
In theory, practice and theory are the same, but in practice they 
are different -- Larry McVoy