Re: [PATCH] 64 bit scsi read/write

Juan Quintela
2001-07-18T08:57:55Z

>>>>> "chris" == Chris Wedgwood <cw@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