"Sounds like the DS8000 architecture allocates DASD in 3390 mod1-sized extents"
Yes, that is exactly what it does. As in the discussion of the MOD27 they say MOD1(1113) x 27=30051(Their number for MOD27). But yes when it is carved in the DS8100 it is actually carved as 30050. Thank You, Terry Martin Lockheed Martin - Citic z/OS and z/VM Performance Tuning and Operating Systems Support Office - 443 348-2102 Cell - 443 632-4191 -----Original Message----- From: The IBM z/VM Operating System [mailto:[email protected]] On Behalf Of Tom Rae Sent: Wednesday, February 10, 2010 6:49 PM To: [email protected] Subject: Re: Number of MOD-27 Cylinders for a z/Linux guest Not quite. Sounds like the DS8000 architecture allocates DASD in 3390 mod1-sized extents, so requesting a 1114 cylinder DASD results in the allocation of two 1113 cylinder extents. The first extent is fully utilized as the first 1113 cylinders of the requested DASD, but only the first cylinder of the second extent is used (as the last cylinder of the requested DASD) and the other 1112 cylinders are allocated but unusable. (nb "extent" is used because it seems to fit, but it's probably not the correct term...) zMan wrote: > > "1112 cylinders are wasted" -- out of 1114? That can't be right! >
