Re: lots and lots of disks again

[Matthew Wilcox <willy@debian.org>]

On Tue, Feb 17, 2004 at 08:57:24AM +0100, Kurt Garloff wrote:
> OK, if you take care to register some major number (or some space for 
> dev_t in newspeak), I'll write the patch to allow the SCSI disks to
> be registered there. We need about 20 bits, IMHO.

20 bits might not be quite big enough.  Assuming 6 bits for partitions,
that gives us 14 bits (16384 devices).  I'd like a fibrechannel person
to chime in here and tell us about the biggest FC array they've ever
seen, but given multipathing showing us the same device multiple times,
that seems a little tight (given how much pain it is to move to a new
numbering scheme).

If we're talking about the numberspace for /dev/drive, I don't see why
we shouldn't take a quarter of the space; ie 2^30 bits.  I suggest we
take 64.0.0.0/30 to leave the top half unused for now.

-- 
"Next the statesmen will invent cheap lies, putting the blame upon 
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince 
himself that the war is just, and will thank God for the better sleep 
he enjoys after this process of grotesque self-deception." -- Mark Twain