The Java heap size in WAS is 512M/1024M. Sizing is based on some ROT from the app vendor so I'm not sure how much leeway there is in making adjustments.
Thanks for all the info & pointers so far. Ray Mrohs > -----Original Message----- > From: Linux on 390 Port [mailto:linux-...@vm.marist.edu] On > Behalf Of Agblad Tore > Sent: Thursday, February 18, 2010 7:25 AM > To: LINUX-390@VM.MARIST.EDU > Subject: Re: What about these VMSTAT 5 numbers? > > Also set the Java Heap as low as possible relative what the > appl needs. > A too big heap just cause problems with cache and longer time for gc. > > Cordialement / Vriendelijke Groeten / Best Regards / Med > Vänliga Hälsningar > Tore Agblad > > Volvo Information Technology > Infrastructure Mainframe Design & Development > SE-405 08, Gothenburg Sweden > E-mail: tore.agb...@volvo.com > > http://www.volvo.com/volvoit/global/en-gb/ > ________________________________________ > From: Linux on 390 Port [linux-...@vm.marist.edu] On Behalf > Of Rob van der Heij [rvdh...@velocitysoftware.com] > Sent: Wednesday, February 17, 2010 16:19 > To: LINUX-390@VM.MARIST.EDU > Subject: Re: What about these VMSTAT 5 numbers? > > On Wed, Feb 17, 2010 at 2:49 PM, Mrohs, Ray > <ray.mr...@usdoj.gov> wrote: > > Hi, > > We are running SLES10 and WebSphere on 1 IFL and 2G storage. These > > bursts of activity seem to happen every few hours. > > Is occasional swapping in the thousands too high if its > going to VDISK? > > What can cause the high 'wa' values? Our info is limited > since this is a > > test partition with no VM performance monitoring (yet). > > Thanks for any insight! > > The "wa" column is % of time waiting for I/O. Your vmstat data shows > swapping, so my guess is that you're swapping to real disk and the > process is in I/O wait for the swap-in. So the virtual machine is too > small for this workload. Since this spike happens frequently, it could > be the JVM Garbage Collection going through the entire JVM heap and > force all pages to be swapped in. Your page cache is rather large for > a WAS workload, might be a good thing to lower the swappiness. > Increasing the virtual machine size or adding VDISK for swap would > help, but can't say whether that fits without seeing z/VM data. > > Did I already mention Performance Monitor? Oh, you did ;-) > -- > Rob van der Heij > Velocity Software > http://www.velocitysoftware.com/ > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO > LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO > LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
