Re: 21 terabytes at NYNEX

Building a system to hold 21Tb has its problems. These are not really related to the file system size of 2Gb as the database would ahve to be raw anyway.

If we assume 10Gb per disk, 12 disks per SCSI channel, 4 channels per Disk controller card you would need 44 disk controllers.

In practice most SMP platforms support about 16 mid plane slots (Though look at some of the new offerings from Sequent and others)

If we need 8 slots for processors and 2 slots for memory then we are left with six slots for controllers. This gives us about 2.9Tb of raw disk to start with. In practice, this would reduce down to 2Tb after RAID, O/S, Swap and load areas where taken into consideration.

21Tb therefore needs to be served by 12 Systems with a distributed system, or more likely a using a series of data marts built on a transaction repository.

I wrote an article on this scale of system for the European Oracle User Group and have built systems upto 5Tb.

If you would like a copy please mail me or wait until it appears on my web page

rgds

davidw

                        Data Management And Warehousing

David M. Walker					Tel: +44 1734 771291
138, Finchampstead Road, Wokingham,		Fax: +44 1734 773058
Berkshire, RG41 2NU, United Kingdom.		Mob: +44  973 387166

http://www.datamgmt.com			  mailto:davidw_at_datamgmt.com


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