You can monitor it and see how much the appl need.
Try 512 to begin with.

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 Mrohs, Ray 
[ray.mr...@usdoj.gov]
Sent: Thursday, February 18, 2010 14:31
To: LINUX-390@VM.MARIST.EDU
Subject: Re: What about these VMSTAT 5 numbers?

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

----------------------------------------------------------------------
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

Reply via email to