SELTAPE algorithm in z/OS
I know SELTAPE was internalized eons ago, but I thought it was internalized as NEXT. I'm seeing what looks like RANDOM on z/OS V1R8. Is this a bug or a feature? My concern is that NEXT always seemed to be the best algorithm to spread out the pain and minimize certain drives getting hammered. Regards, Tom Conley -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: SELTAPE algorithm in z/OS
What would you like to happen if the first mount is for 10 EXCPs and the next one is for 10M? -Original Message- From: Thomas Conley [mailto:snip] Sent: Wednesday, May 23, 2007 11:16 AM To: IBM-MAIN@BAMA.UA.EDU Subject: SELTAPE algorithm in z/OS I know SELTAPE was internalized eons ago, but I thought it was internalized as NEXT. I'm seeing what looks like RANDOM on z/OS V1R8. Is this a bug or a feature? My concern is that NEXT always seemed to be the best algorithm to spread out the pain and minimize certain drives getting hammered. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: SELTAPE algorithm in z/OS
I believe it's WAD or feature. But why next, I would think random would be best in spreading out the pain. And, if you don't do a lot of mounts, or you hit a lull, then you're always using the low order UCB's. Thomas Conley [EMAIL PROTECTED] Sent by: IBM Mainframe Discussion List IBM-MAIN@BAMA.UA.EDU 05/23/2007 02:15 PM Please respond to IBM Mainframe Discussion List IBM-MAIN@BAMA.UA.EDU To IBM-MAIN@BAMA.UA.EDU cc Subject SELTAPE algorithm in z/OS I know SELTAPE was internalized eons ago, but I thought it was internalized as NEXT. I'm seeing what looks like RANDOM on z/OS V1R8. Is this a bug or a feature? My concern is that NEXT always seemed to be the best algorithm to spread out the pain and minimize certain drives getting hammered. Regards, Tom Conley -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] 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 [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: SELTAPE algorithm in z/OS
On May 23, 2007, at 1:15 PM, Thomas Conley wrote: I know SELTAPE was internalized eons ago, but I thought it was internalized as NEXT. I'm seeing what looks like RANDOM on z/OS V1R8. Is this a bug or a feature? My concern is that NEXT always seemed to be the best algorithm to spread out the pain and minimize certain drives getting hammered. Regards, Tom Conley Tom, H.. I guess I disagree. When next is used (IMO) the same drive (lowest addr) tends to get used a lot more than the rest. I complained to IBM a long time ago that they weren't rotating the drives enough. When I changed it random all the drives seemed to get used but the operators complained as they had to do more work. Meanwhile tape errors went down considerably. Ed -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
