[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference rdgeng::cics_technical

Title:Discussion of CICS technical issues
Moderator:IOSG::SMITHF
Created:Mon Mar 13 1995
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:192
Total number of notes:680

143.0. "SFS log volume growth" by CSC32::D_CAREW () Wed Oct 30 1996 21:24

T.RTitleUserPersonal
Name
DateLines
143.1MUFFIT::gerryGerry ReillyFri Nov 01 1996 09:2649
143.2Customer says cold starting the sfs is only wayCSC32::D_CAREWTue Nov 05 1996 22:5157
143.3Some answers, but not all...:-)MUFFIT::helenHelen PrattWed Nov 06 1996 15:2040
143.4Steps done; re-use not obvious?CSC32::D_CAREWThu Dec 12 1996 22:3725
143.5More thoughtsMUFFIT::gerryGerry ReillyFri Dec 13 1996 12:0636
143.6more info from customer...CSC32::C_BENNETTTue Mar 11 1997 15:2177
    A follow up issue from the customer...
    
	Could you pass the following on to Fiona Smith's group?  It is 
    probably of interest to them.

	We had a another occurrence of c961029-4156 on our development server 
(gecao2, cicscst1).  We had been having a number of U8022 region abends 
caused by the application programmers putting a connect statement in their 
transaction programs.  During a number of the abends, we also had one or 
more of the following messages:

ERZ025047I/0161 02/24/97 06:34:59 cicscst1     : An Open File Descriptor 
has been left open on the SFS for file 
'/.:/cics/sfs/gecao2'/'cicscst1cicsnrectsqfil', index 'cicsnrectsqidx'

	It may not have always been the same file.  Seventeen days after we had 
the first of these, the sfs log volume became full and we had to do a cold 
start on sfs to recover.  This also goes back to where I had informed Dave 
Carew that the instructions that we had been given to prevent the log from 
becoming full did not appear to have any affect on the sfs log.

	We have two theories about the sfs log full conditions that we have 
experienced over the past 5 months.  The first is obvious by the above 
message.  When we started seeing these we shortly thereafter got into a 
predicament.  The other may or may not have any affect but I thought I 
would mention it.  We have never experienced any sfs log full on gecao4. 
 Nor do we notice any periods of it getting any where near full.  It always 
appears that the number of free pages is very near the total number.  On 
gecao1, where we have experienced it a few times in the past, it seems to 
approach full and then cleans itself up, but never to the number of free 
pages that it had before.  The BIG difference between the two systems is 
that on gecao4, the log was created at a very large size.  On gecao1, we 
have a number of smaller regions that have been added to it as the need for 
more arose.  Could the sfs logging facility have a problem handling a 
number of smaller regions that have been added vs. one larger region?  To 
illustrate my point, I have attached below the output from a tkadmin 
command:

gecao1> tkadmin query pvol log_Sgecao1_P
Information about physical volume log_Sgecao1_P
All sizes and offsets are in pages. Page Size is: 4 Kbytes
Mapped to logical volume log_Sgecao1
chunkSize: 64
numRegions: 5
region 0: disk: /dev/rvol/rootdg/log_Sgecao1 offset:     0 size: 32704
region 1: disk: /dev/rvol/rootdg/log_Sgecao1-2 offset:     0 size: 16320
region 2: disk: /dev/rvol/rootdg/log_Sgecao1-3 offset:     0 size: 32704
region 3: disk: /dev/rvol/rootdg/log_Sgecao1-4 offset:     0 size: 65472
region 4: disk: /dev/rvol/rootdg/log_Sgecao1-5 offset:     0 size: 65472
total size: 212672

gecao4> tkadmin query pvol log_Sgecao4_P
Information about physical volume log_Sgecao4_P
All sizes and offsets are in pages. Page Size is: 4 Kbytes
Mapped to logical volume log_Sgecao4
chunkSize: 64
numRegions: 1
region 0: disk: /dev/rvol/rootdg/log_Sgecao4 offset:     0 size: 131008
total size: 131008

	We are proposing that as a regularly scheduled task (we have mentioned 
five to six months) that we will cold start the sfs to clear up the log 
volume.  We have also decided that during the next cold start on gecao1, 
that we attempt to create the log as one large region like we have on 
gecao4.

	Do any of the Digital CICS people have any comment on what I have stated 
here?

Thank you,

Brian Schroeder
email: [email protected]

Brian Schroeder
8*235-7405