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
