Lizette, What is the freespace(nn,nn) parameter in your CDS VSAM define?
I suspect you are running with something like 50,50 based on your comment. If you are 96% full with 62% freespace that tells me that a section of your CDS is experiencing a lot of activity and will drive the file to 100%. Probably at the most inopportune time. Splits for a HSM CDS should not be a concern. It's not like anyone is waiting with bated breath for a migrate or backup to finish. Like any other VSAM KSDS, the HSM CDSs need to be re-organized from time to time. Thank You, Dave O'Brien NIH Contractor ________________________________________ From: Lizette Koehler [[email protected]] Sent: Thursday, January 17, 2013 9:27 AM To: [email protected] Subject: Re: DFHSM CDS size versus multi-cluster I think if you issue the command F dfhsm,Q CDS you may find in the ARC0148I messages that there are two pieces of information to explain if your file needs to be reorg'd First is the number you get is %Full. However there is a second number %Freespace. What I have seen in my shop is we are running 96% full. However we have 62% freespace. Which to me does not indicate a need to reorg. According to IBM and Share presentations, the xCDS files should not be reorg'd. That when you reorg an xCDS HSM has to starting splitting the files again which will slow down the process for a little bit. Once enough splits occur so there is room to insert records, it is fine. So the questions are 1) Is the xCDS so big it needs a reorg? 2) Do I need to resize the xCDS dataset? Once those are answered, you can figure out when to take an outage on HSM. The other option is to change from VSAM to VSAM RLS structure for your xCDS datasets. You may also wish to review if the Journal dataset should be changed as well. Lizette > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf > Of af dc > Sent: Thursday, January 17, 2013 5:20 AM > To: [email protected] > Subject: DFHSM CDS size versus multi-cluster > > Hello, > I'm running z/os V1.12 and I've got my BCDS filled with 85%. It's size is > 6500 CYLS with no SEC space. > VSAM characteristics are: > SHROPTNS(3,3) RECOVERY UNIQUE NOERASE > UNORDERED TEMP-EXP NOREUSE NONSPANNED > > INDEXED NOWRITECHK NOIMBED NOREPLICAT > EXTENDED EXT-ADDR > > In a short time I'll have to create a new BCDS, so, in your opinion what's advisable to > have (performance aspect, backup considerations?, etc)?? > 1) a bigger BCDS or > 2) multi cluster > > Note: > - DFHSM cdss are shared among 3 lpars > > Any hint is welcome? > Many thx, Antonio Cecilio. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
