But... 262668 is NOT a multiple of 3339.. (and to put my math hat on: you can also tell because 236 isn't divisible by 3)
Scott On Wed, Feb 10, 2010 at 4:54 PM, Hodge, Robert L <[email protected]>wrote: > Note that IBM is planning to support up to 262668 cylinders with Extended > Address Volumes (EAV) on a DS8000. 262668 is a multiple of 1113. 236 x 1113 > = 262668. Maybe that is the meaning of the last sentence. "In fact, integral > multiples of 3339 cylinders should be considered for future compatibility." > > -----Original Message----- > From: The IBM z/VM Operating System [mailto:[email protected]] On > Behalf Of Brian Nielsen > Sent: Wednesday, February 10, 2010 3:30 PM > To: [email protected] > Subject: Re: Number of MOD-27 Cylinders for a z/Linux guest > > To quote the DS8000 Architecture and Implementation Redbook (SG24-6786, p > g > 101): > > "If the number of cylinders specified is not an integral multiple of 1113 > > cylinders, then some space in the last allocated extent is wasted. For > > example, if you define 1114 or 3340 cylinders, 1112 cylinders are wasted. > > For maximum storage efficiency, you should consider allocating volumes > > that are exact multiples of 1113 cylinders. In fact, integral multiples o > f > 3339 cylinders should be consider for future compatibility." > > That last sentence has always peaked my interest. > > Brian Nielsen > > > On Wed, 10 Feb 2010 14:33:09 -0700, Scott Rohling > <[email protected]> wrote: > > >I think this whole post got confused :-) No one said a 3390-27 is 300 > 51 > >cylinders. I said that I would consider making one 30049 cylinders > > since > >that equates to 3 3390-9 plus cylinder 0 for a volume label. (3x10016 > + > 1) > > > >A supposed 'standard' 3390-27 is 32760 cyls -- but past 3390-9 -- it's > >really arbitrary and can be 'whatever you like'... > > > >Scott >
