Re: DSS EXCP counts
I believe a modern translation of the acronym is Estimated eXecutions of the things that replaced Channel Programs. :-) Seriously, I'd say you are seeing evidence of some aggressive I/O avoidance. That is, you are getting the same (or more) data in fewer operations. -Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Schwarz, Barry A Sent: Thursday, May 10, 2007 2:06 PM To: IBM-MAIN@BAMA.UA.EDU Subject: DSS EXCP counts Can someone give me a hint why the EXCP count for a full volume dump for an unchanged volume would occasionally vary by ~400 between one execution and the next. I run a set of jobs weekly to dump just my system packs to tape using DFDSS. Several of the packs, such as the DLIB volumes, haven't changed in months/years (2.10 is out of support). Most weeks, the EXCP count is very close to last week's count for each volume. Once in a while, the count will jump up for a one week (or occasionally a few weeks) and then return to normal. When it happens, it seems to happen for all the jobs. Some of the packs are pretty full and the delta is less than 10%. But my SMPPTS dataset is alone on a pack and has been almost empty since my last accept run. Its normal EXCP count is 700 and an increase of 400 is a significant percentage. The times for the jobs do not show a corresponding delta. It doesn't seem to make any practical difference but it has piqued my curiosity. NOTICE: This electronic mail message and any files transmitted with it are intended exclusively for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged information. Any unauthorized review, use, printing, saving, copying, disclosure or distribution is strictly prohibited. If you have received this message in error, please immediately advise the sender by reply email and delete all copies. -- 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: DSS EXCP counts
Barry I just got my interest piqued a little by your question. So, here is what got my interest -- why would you take full volume dumps if they haven't changed in months/years? Tom Moulder -Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Schwarz, Barry A Sent: Thursday, May 10, 2007 2:06 PM To: IBM-MAIN@BAMA.UA.EDU Subject: DSS EXCP counts Can someone give me a hint why the EXCP count for a full volume dump for an unchanged volume would occasionally vary by ~400 between one execution and the next. I run a set of jobs weekly to dump just my system packs to tape using DFDSS. Several of the packs, such as the DLIB volumes, haven't changed in months/years (2.10 is out of support). Most weeks, the EXCP count is very close to last week's count for each volume. Once in a while, the count will jump up for a one week (or occasionally a few weeks) and then return to normal. When it happens, it seems to happen for all the jobs. Some of the packs are pretty full and the delta is less than 10%. But my SMPPTS dataset is alone on a pack and has been almost empty since my last accept run. Its normal EXCP count is 700 and an increase of 400 is a significant percentage. The times for the jobs do not show a corresponding delta. It doesn't seem to make any practical difference but it has piqued my curiosity. No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.1/805 - Release Date: 5/15/2007 10:47 AM -- 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: DSS EXCP counts
On Tue, 15 May 2007 15:57:37 -0500, Tom Moulder [EMAIL PROTECTED] wrote: Barry I just got my interest piqued a little by your question. So, here is what got my interest -- why would you take full volume dumps if they haven't changed in months/years? I'm sure he can answer for himself... but I'll here is one answer. if you run backups every week and they have a certain retention period (say 4 weeks), you need to keep running them or you have no backups. This is much easier than looking at the data on every volume on an individual basis to figure out when you need to back it up and how long you need to keep it. Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group: G-ITO mailto:[EMAIL PROTECTED] z/OS and OS390 expert at http://searchDataCenter.com/ateExperts/ Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.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: DSS EXCP counts
The process runs every week. Rather than try to remember if something has been updated, it's easier to run the entire sequence. -Original Message- From: Tom Moulder [mailto:tom_snip] Sent: Tuesday, May 15, 2007 1:58 PM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: DSS EXCP counts Barry I just got my interest piqued a little by your question. So, here is what got my interest -- why would you take full volume dumps if they haven't changed in months/years? Tom Moulder -- 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
DSS EXCP counts
Can someone give me a hint why the EXCP count for a full volume dump for an unchanged volume would occasionally vary by ~400 between one execution and the next. I run a set of jobs weekly to dump just my system packs to tape using DFDSS. Several of the packs, such as the DLIB volumes, haven't changed in months/years (2.10 is out of support). Most weeks, the EXCP count is very close to last week's count for each volume. Once in a while, the count will jump up for a one week (or occasionally a few weeks) and then return to normal. When it happens, it seems to happen for all the jobs. Some of the packs are pretty full and the delta is less than 10%. But my SMPPTS dataset is alone on a pack and has been almost empty since my last accept run. Its normal EXCP count is 700 and an increase of 400 is a significant percentage. The times for the jobs do not show a corresponding delta. It doesn't seem to make any practical difference but it has piqued my curiosity. -- 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: DSS EXCP counts
Schwarz, Barry A wrote: Can someone give me a hint why the EXCP count for a full volume dump for an unchanged volume would occasionally vary by ~400 between one execution and the next. DFDSS uses chained I/Os, where the completion of one I/O triggers the next one in the same CCW chain. Under some conditions delays in interrupt handling, or channel/controller busy can break the chain and necessitate a restart. If you're really curious about this, try to reconstruct what else is going on (SMF, RMF records) when the counts increase. Gerhard Postpischil Bradford, VT new e-mail address: gerhardp (at) charter (dot) net -- 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
