On May 1, 2014, at 3:14 PM, Ron Hawkins <[email protected]> wrote:
> Shmuel's reply prompts me to suggest that you consider what lies outside the > nine dots. > > Firstly, would you consider thin provisioning of the installation volumes and > SYSRES? This will get you onto 3390-A for these volumes using any size you > want. Why is this good? Because DVE is also good. If you start out with 32K > Cyls and later find it is not enough, just make the volume bigger. You need > 40K Cyls, then just add 8K Cyls to the existing volumes. Sounds easy, but I'm > not a software jockey. > > Second thing is ignore the previous paragraph and just allocate full sized > 3390-A volumes with 262K Cyls. If you don't use the space on the volume then > you don't use space in the disk array, and I think it will be some time > before Serverpac manages to fill one of these pupies. All those that worked > with RVA will remember over provisioning with 3390-3 when you only needed > 3390-1 for your JES2 Checkpoint. This is the same thing. > > Finally, make all the data sets ten (yes 10) times larger than they need to > be, with ten times the directory blocks you think you want. It is the same > principle as above: if you don't use the space on the volume then you don't > use the space in the disk array, > > OK, there is a sanity check on the the space you use in the array because of > the page allocation boundaries. IBM uses 1GB pages, HDS uses 32MB pages, and > I think EMC use 14MB pages. So an empty volume with just a VTOC & VVDS will > consume 1GB, 32MB, and 14MB respectively from the pool of each vendor. For > EMC and HDS the fragmentation generated by the Cylinder allocation area with > just a VTOC , and the empty space in datasets is fairly small and does not > dramatically inflat the pool usage (remember NCL?), but for IBM the 1GB page > size may need some monitoring. > > Embrace the future of z, because it is already here. Now you guys that know > better can shoot me down: shields are up :-) This goes along with my response to this thread: people are still piddling around with mod 9’s and even mod 3’s? Once dynamic pooling became available on our Hitachi VSP I reconfigured all our volumes to mod 54’s. I’ve provisioned volumes with 120% of the array’s physical capacity, but only 60% of that physical capacity is actually in use, so I’m good. I have fewer volumes to worry about, and I can let the storage controller worry about performance and efficient use of space. It’s the 21st century; let’s live like it. -- Curtis Pew ([email protected]) ITS Systems Core The University of Texas at Austin ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
