Hi, The SMS address space is one of the Top 10 I/O consumers on most z/OS systems here. It is small compared to DB2 and IMS but large compared to most other persistent tasks.
Has anyone ever had a conversation with IBM or raised a requirement to reduce the physical I/O to the COMMDS when the SMSPLEX is identical to the Sysplex? Maybe this is a dumb question and there is some obvious tuning knob I have been missing. I noticed we do have interval set to 10 seconds instead of the default 15 and it has been that way apparently since we implemented SMS in the 1990's. When I was looking at this it just struck me as really odd that almost every other product we have that that does checkpoint processing to communicate system status can optionally exploit the coupling facility or XCF but not DFSMS. I keep an eye on Top I/O consumers looking for any changes and usually skipped over SMS but I had a "Why is the sky blue?" moment today. JES2, Thruput Manager, CA-MIM all exploit XCF or Coupling Facility structures to exchange status information and reduce data set "checkpoint" I/O. D SMS,OPTIONS IGD002I 19:54:14 DISPLAY SMS 756 ACDS = SYS2.SMS.ACDS COMMDS = SYS2.SMS.COMMDS INTERVAL = 10 DINTERVAL = 150 SMF_TIME = YES CACHETIME = 3600 CF_TIME = 3600 PDSE_RESTARTABLE_AS = YES PDSE_BMFTIME = 3600 PDSE1_BMFTIME = 3600 PDSE_LRUTIME = 60 PDSE1_LRUTIME = 60 PDSE_LRUCYCLES = 15 PDSE1_LRUCYCLES = 15 LOCAL_DEADLOCK = 15 GLOBAL_DEADLOCK = 4 REVERIFY = NO DSNTYPE = PDS ACSDEFAULTS = NO PDSESHARING = EXTENDED OVRD_EXPDT = NO SYSTEMS = 8 PDSE_HSP_SIZE = 0MB PDSE1_HSP_SIZE = 0MB USE_RESOWNER = YES RLS_MAX_POOL_SIZE = 100MB RLSINIT = YES RLSTMOUT = 0 CICSVR_INIT = NO COMPRESS = GENERIC CICSVR_DSNAME_PREFIX = DWW. CICSVR_RCDS_PREFIX = DWW CICSVR_GRPNAME_SUFFIX = PROD CICSVR_ZZVALUE_PARM = CICSVR_UNDOLOG_CONTROL = CICSVR_UNDOLOG_PREFIX = DWW CICSVR_BACKOUT_CONTROL = CICSVR_GENERAL_CONTROL = Rls_MaxCfFeatureLevel = A RlsAboveTheBarMaxPoolSize = 0 RlsFixedPoolSize = 0 PDSE_MONITOR = (YES,0,0) PDSE1_MONITOR = (YES,0,0) PDSE_DIRECTORY_STORAGE = 2000M PDSE1_DIRECTORY_STORAGE = 2000M PDSE_BUFFER_BEYOND_CLOSE = YES PDSE1_BUFFER_BEYOND_CLOSE = YES GDS_RECLAIM = YES DSSTIMEOUT = 0 BLOCKTOKENSIZE = NOREQUIRE FAST_VOLSEL = OFF IGD002I 19:54:14 DISPLAY SMS TRACE = OFF SIZE = 128K TYPE = ERROR JOBNAME = * ASID = * TRACING EVENTS: MODULE = ON SMSSJF = ON SMSSSI = ON ACSINT = ON OPCMD = ON CONFC = ON CDSC = ON CONFS = ON MSG = ON ERR = ON CONFR = ON CONFA = ON ACSPRO = ON IDAX = ON DISP = ON CATG = ON VOLREF = ON SCHEDP = ON SCHEDS = ON VTOCL = ON VTOCD = ON VTOCR = ON VTOCC = ON VTOCA = ON RCD = ON DCF = ON DPN = ON TVR = ON DSTACK = ON UAFF = ON DEBUG = ON VOLSELMSG = (OFF,0) TYPE = ERROR JOBNAME = * ASID = * STEPNAME = * DSNAME = * Anyone have any thoughts on the list or privately if you don't want to comment on IBM-MAIN is fine too? Best Regards, Sam Knutson, GEICO System z Performance and Availability Management mailto:[EMAIL PROTECTED] (office) 301.986.3574 "Think big, act bold, start simple, grow fast..." ==================== This email/fax message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this email/fax is prohibited. If you are not the intended recipient, please destroy all paper and electronic copies of the original message. ---------------------------------------------------------------------- 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