Fwd: SHARED MEMORY ISSUE - SORRY FOR DIRECTLY ASKING THIS..

I'm posting this to CDI and the Linux List for Julia who's having a problem the list may be able to help with. Please include her address (below) in you reply: Art S. Kagel ----- Original Message ----- From: Julia M <juliamrus@YAHOO.COM> At: 10/ 5 22:25 <SNIP> I am trying to increase shared memory setting on our server running on a DELL poweredge 6650 with 4GB RAM and linux 2.4 (enterprise). For some reason if I set the buffers value to anything morethan 700000 it crashed saying can't allocate shared memory. Here I don't want to increase the Virtual segment but the Buffers. I tried the following SHMMAX values but Informix doesn't seems to like any of the values set through sysctl.conf during the server bootup. #kernel.shmmax = 33554432 - release note value #kernel.shmmax = 134217728 #kernel.shmmax = 2*536870912 (all above values failed with more than 700000 buffers) SHMBASE 0x50000000 # Shared memory baseaddress in onconfig - (release note says this should be set to 0x1000000L. But when you do that you can't allocate shared memory more than 700 MB) kernel.shmmax = 536870912 (current value) kernel.shmmin = 1 kernel.shmmni = 128 kernel.shmseg = 128 kernel.semmns = 4096 kernel.semmnu = 4096 kernel.semume = 32 kernel.semmap = 4096 kernel.semmsl = 100 I have no clue why It can't go beyond the shared memeory value of 1896000 KB (When buffers value set above 700000). What am I missing here?? Any answer to this is much appreciated. I have included the cat /proc/meminfo, onconfig and online.log values for you to get an idea. cat /proc/meminfo total: used: free: shared: buffers: cached: Mem: 3692048384 2287001600 1405046784 1521373184 107352064 151183360 Swap: 2146754560 0 2146754560 MemTotal: 3605516 kB MemFree: 1372116 kB MemShared: 1485716 kB Buffers: 104836 kB Cached: 147640 kB SwapCached: 0 kB Active: 136932 kB Inact_dirty: 1601260 kB Inact_clean: 0 kB Inact_target: 917488 kB HighTotal: 2752448 kB HighFree: 699988 kB LowTotal: 853068 kB LowFree: 672128 kB SwapTotal: 2096440 kB SwapFree: 2096440 kB BigPagesFree: 0 kB Informix Dynamic Server Version 7.31.UD6 -- On-Line -- Up 09:23:06 -- 1896196 Kbytes Configuration File: /usr/informix/etc/onconfig.malco #************************************************************************** # # INFORMIX SOFTWARE, INC. # # Title: onconfig.std # Description: Informix Dynamic Server Configuration Parameters # #************************************************************************** # Root Dbspace Configuration ROOTNAME rootdbs # Root dbspace name ROOTPATH /usr/informix/data/db01 # Path for devicecontaining root dbspace ROOTOFFSET 2 # Offset of rootdbspace into device (Kbytes) ROOTSIZE 1048576 # Size of root dbspace (Kbytes) # Disk Mirroring Configuration Parameters MIRROR 0 # Mirroring flag (Yes = 1, No = 0) MIRRORPATH # Path for devicecontaining mirrored root MIRROROFFSET 0 # Offset into mirrored device (Kbytes) # Physical Log Configuration PHYSDBS plogdbs # Location (dbspace) of physical log PHYSFILE 262140 # Physical log file size (Kbytes) # Logical Log Configuration LOGFILES 510 # Number of logicallog files LOGSIZE 1024 # Logical log size (Kbytes) # Diagnostics MSGPATH /var/informix/online.log # System message log file path CONSOLE /dev/tty1 # System consolemessage path ALARMPROGRAM /usr/informix/etc/log_full.sh # Alarm program path SYSALARMPROGRAM /usr/informix/etc/evidence.sh # System Alarm program path TBLSPACE_STATS 1 # System Archive Tape Device TAPEDEV /dev/vm0 # Tape device path#TAPEDEV /dev/null # Tape device path TAPEBLK 512 # Tape block size (Kbytes) TAPESIZE 100000000 # Maximum amount ofdata to put on tape (Kbytes) # Log Archive Tape Device LTAPEDEV /dev/vm0 # Log tape device path#LTAPEDEV /dev/null # Log tape device path LTAPEBLK 512 # Log tape block size (Kbytes) LTAPESIZE 100000000 # Max amount of datato put on log tape (Kbytes) # Optical STAGEBLOB # Informix Dynamic Server/Optical staging area # System Configuration SERVERNUM 1 # Unique idcorresponding to a Dynamic Server instance DBSERVERNAME malco_1 # Name of defaultdatabase server DBSERVERALIASES malco_2,mallive # List ofalternate dbservernames NETTYPE ipcshm,5,50,CPU # Configure pollthread(s) for nettype NETTYPE soctcp,2,25,NET # Configure pollthread(s) for nettype DEADLOCK_TIMEOUT 30 # Max time to wait oflock in distributed env. RESIDENT 1 # Forced residency flag (Yes = 1, No = 0) MULTIPROCESSOR 1 # 0 forsingle-processor, 1 for multi-processor NUMCPUVPS 7 # Number of user (cpu)vps SINGLE_CPU_VP 0 # If non-zero, limitnumber of cpu vps to one NOAGE 0 # Process aging AFF_SPROC # Affinity startprocessor AFF_NPROCS # Affinity number ofprocessors # Shared Memory Parameters #LOCKS 65536 # Maximum number of locks LOCKS 250000 BUFFERS 648216 # Maximum number ofshared buffers NUMAIOVPS 16 # Number of IO vps PHYSBUFF 96 # Physical log buffer size (Kbytes) LOGBUFF 32 # Logical log buffer size (Kbytes) LOGSMAX 512 # Maximum number oflogical log files CLEANERS 108 # Number of buffercleaner processes SHMBASE 0x50000000 # Shared memory baseaddress SHMVIRTSIZE 262144 # initial virtualshared memory segment size SHMADD 65536 # Size of new sharedmemory segments (Kbytes) SHMTOTAL 2048000 # Total shared memory (Kbytes). 0=>unlimited CKPTINTVL 300 # Check point interval (in sec) LRUS 128 # Number of LRU queues LRU_MAX_DIRTY 2 # LRU percent dirtybegin cleaning limit LRU_MIN_DIRTY 1 # LRU percent dirtyend cleaning limit LTXHWM 40 # Long transactionhigh water mark percentage LTXEHWM 60 # Long transactionhigh water mark (exclusive) TXTIMEOUT 0x12c # Transaction timeout (in sec) STACKSIZE 32 # Stack size (Kbyt

ART KAGEL, BLOOMBERG/ 499 PARK wrote: > I'm posting this to CDI and the Linux List for Julia who's having a problem the > list may be able to help with. Please include her address (below) in you reply: Nope - there's the IIUG archive, and there's groups.google.com, ... > ----- Original Message ----- > From: Julia M <juliamrus@YAHOO.COM> > At: 10/ 5 22:25 > <SNIP> > I am trying to increase shared memory setting on our > server running on a DELL poweredge 6650 with 4GB RAM > and linux 2.4 (enterprise). > For some reason if I set the buffers value to anything > morethan 700000 it crashed saying can't allocate > shared memory. > Here I don't want to increase the Virtual segment but > the Buffers. You're on a 32-bit system (IDS 7.31.UD6). You won't get to all 4 GB available as buffers in a single IDS instance because a 32-bit system only has 4 GB total memory, and some of that has to be used for the code, shared libraries, and per-process (as opposed to per-thread) stack and heap space. You might, perhaps, reach 3GB; you'll be hard pushed to reach much more. The next problem is the way that Linux places shared libraries in memory -- be grateful you aren't using RHEL v3 update 3 with its Exec-Guard and randomized mapping (hi Ron!). Basically, you need to have a 3GB gap in the memory map available to allocate your 3 GB chunk of shared memory. I'm not clear on all the ins and outs of how you do that, but you need to ensure that shared libraries are loaded at a high enough address and SHMBASE is set low enough that there is a 3GB gap available to use. (One reason why its going to be hard to use more than 3 GB is that there's even less room for manoeuvre as you increase the space allocated to shared memory. > I tried the following SHMMAX values but Informix > doesn't seems to like any of the values set through > sysctl.conf during the server bootup. > > > #kernel.shmmax = 33554432 - release note value > #kernel.shmmax = 134217728 > #kernel.shmmax = 2*536870912 > (all above values failed with more than 700000 > buffers) > > SHMBASE 0x50000000 # Shared memory base> address in onconfig - > (release note says this should be set to 0x1000000L. > But when you do that you can't allocate shared memory > more than 700 MB) > > > kernel.shmmax = 536870912 (current value) > kernel.shmmin = 1 > kernel.shmmni = 128 > kernel.shmseg = 128 > kernel.semmns = 4096 > kernel.semmnu = 4096 > kernel.semume = 32 > kernel.semmap = 4096 > kernel.semmsl = 100 > > > > I have no clue why It can't go beyond the shared > memeory value of 1896000 KB (When buffers value set > above 700000). > What am I missing here?? > Any answer to this is much appreciated. > > I have included the cat /proc/meminfo, onconfig and > online.log values for you to > get an idea. > > > cat /proc/meminfo > total: used: free: shared: buffers: > cached: > Mem: 3692048384 2287001600 1405046784 1521373184 > 107352064 151183360 > Swap: 2146754560 0 2146754560 > MemTotal: 3605516 kB > MemFree: 1372116 kB > MemShared: 1485716 kB > Buffers: 104836 kB > Cached: 147640 kB > SwapCached: 0 kB > Active: 136932 kB > Inact_dirty: 1601260 kB > Inact_clean: 0 kB > Inact_target: 917488 kB > HighTotal: 2752448 kB > HighFree: 699988 kB > LowTotal: 853068 kB > LowFree: 672128 kB > SwapTotal: 2096440 kB > SwapFree: 2096440 kB > BigPagesFree: 0 kB > > Informix Dynamic Server Version 7.31.UD6 -- > On-Line -- Up 09:23:06 -- 1896196 Kbytes > > Configuration File: /usr/informix/etc/onconfig.malco >[...] > ================================================================== > > This is what happened when I try to increase the > number of buffers beyond=700000 > > > 04:30:03 Informix Dynamic Server Stopped. > > 04:36:37 Segment locked: addr=0x50000000,> size=1692237824 >[...] > 04:36:37 Segment locked: addr=0x50000000,> size=1692237824 > > Fri Sep 10 04:36:38 2004 > > 04:36:38 Assert Failed: Internal error: embedded> mutex, name = support > > 04:36:38 Informix Dynamic Server Version 7.31.UD6 > 04:36:38 Who: Session(0, @, 0, 0) > Thread(1, main_thread, 0, 1) > File: mt.c Line: 6532 > 04:36:39 See Also: /tmp/af.3e9a2b6, shmem.3e9a2b6.0 > 04:36:42 Error writing '/tmp/shmem.3e9a2b6.0' errno => 14 > 04:36:42 mt.c, line 6532, thread 1, proc id 1417,> Internal error: embedded mutex, name = support > 04:36:42 PANIC: Attempting to bring system down -- Jonathan Leffler #include <disclaimer.h> Email: jleffler@earthlink.net, jleffler@us.ibm.com Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/