Johnny, The saving in hardware assisted compression is in decompression - when you read it. Look at what should be a much lower CPU cost to decompress the files during restore and decide if the speed of restoring the data concurrently is worth the increase in CPU required to back it up in the first place.
Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of > Johnny Luo > Sent: Thursday, December 02, 2010 2:13 AM > To: IBM-MAIN@bama.ua.edu > Subject: [IBM-MAIN] Hardware-assisted compression: not CPU-efficient? > > Hi, > > DSS DUMP supports COMPRESS/HWCOMPRESS keyword and I found out in my test > that HWCOMPRESS costs more CPU than COMPRESS. > > Is it normal? > > Currently we're dumping huge production data to tape and in order to > alleviate the tape channel utilization we need to compress the data before > writing to tape. It works well but the cpu usage is a problem cause we have > many such backup jobs running simultaneously. > > If hardware-assisted compression cannot reduce the cpu overhead, I will > consider using resource group to cap those jobs. > > Best Regards, > Johnny Luo > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
