XOR Commands Meeting

George Penokie GOP at RCHVMP3.VNET.IBM.COM
Wed Nov 23 06:54:37 PST 1994


I just read through the minutes of the 11/7/94 XOR meeting (yes some of
us do actually read minutes) and I have some major concerns.

It looks to me like there are proposals to define things (like redundancy
goups and RAID 5 mode pages, addressing etc.) that are already defined within
the SCC Standard. The SCC model covers all levels of the system and this
includes drive that have SACL like functions built into them.  If a drive
wants to be a storage array (which it can) then it must follow the rules
for SCC devices. And like it or not putting XOR functions in a drive that
controls the flow of data to other drives to do RAID functions is an SCC
device.

I do not have a problem with the XOR group defining new drive commands to
deal with the movment of data between drives, as defined in Seagate's XOR
Commands proposal.  But it appears there is a movement to expand beyond
that original charter.  This expansion can only bring confusion to the
industry if terms and concepts used in the XOR proposals are not consistant
with the defination of the those same terms in the SCC standard
(ie Redundancy group, addressing, etc.).

Bye for now,
George




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