One thing no one else has mentioned is that one of the strengths of having many disks is that you can be doing I/O on many more drives at the same time. After all, you can only do 1 read or write from physical disk at a time. Of course, with the huge amounts of cache, that changes. If your datacenter had 100 TB of storage, and each physical disk stored 1 TB, you would only have a maximum of 100 physical I/O's happening at any one point in time. Since most data is not distributed equally, probably only 20-40 I/O's would be happening at once.
Just something to think about! Also, I just read something this morning about some new solid state DASD that IBM announced. This is from the announcement letter today: The IBM 100 GB 1.8-inch and 2.5-inch solid-state drives (SSD) provide high-performance, reliable solutions for high-capacity enterprise applications with a moderate read and write mix by employing a 6 GBps SATA interface and MLC NAND technology. These solid-state drives present an opportunity to simplify your local storage infrastructure to help maintain overall maintenance and cooling cost, while considering remote storage solutions for end-to-end data availability. You can get this from today's announcement letters. It's the 1st one. Eric Bielefeld Systems Programmer ---- "Roberts wrote: > >But this surely has little if anything to do with the size of the physical > >drives used by the makers of storage subsystems. > > If storage array makers are using 1TB drives vs the 73GB that was typical > just a couple years back, this should translate to many fewer drives. Which > should translate to lower power consumption and heat generation, which was > the original point I was trying to make. And John Eells can tell us if going > to the 2.5 in form factor is in their plans. If so, this could indicate that > power consumption will be ever further reduced. > > One thing that would be interesting to learn: how much of a typical data > center's power consumption is attributable to storage subsystems, including > RAID and Virtual Tape? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
