> -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of Bruce Black > Sent: Saturday, September 02, 2006 8:32 PM > To: [email protected] > Subject: Re: IBM announces Encrypting tape drives > > > The Encryption Facility can use HW-based compression before > > encryption, all on the server. (One has to specify its use because > > there is no way to uncompress the data on a non-z server.) > > ??? the hardware compression (CPACF) has been available on all systems > for many years and generations, long before zSeries. I am sure it is > available on any system which is still in use. Even if it wasn't there, > the op system contains software emulation (at a CPU price, of course). > > I think the main reason that compression is optional is for data that is > already compressed or naturally incompressible; compress CPU time goes > up on such data as it tries to find ways to compress it > > -- > Bruce Black /snip/ ITYM: CMPSC is compression, CPACF is crypto. CMPSC has been around for many years (about 10 or more). CPACF is z/990.
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