First of all, this is a JRE issue, not Tomcat! Depending on your Operating system (Windows, *nix, etc.), whether it's a 32 or 64 bit version, and what JRE you're using, the limit is different. You can get pretty good info from you JRE vendor about how it uses memory - Sun has several good articles on it - especially how they relate to Garbage Collection.
Under 32 bit Windows, the JRE process is limited to 2 GB of total memory - including the memory that the JRE needs other than the heap controlled by the -Xmx setting. The practical limit is about 1250 MB for 32-bit Windows with a 1.5 or 1.6 Sun JRE. The limit for 64-bit Windows is insanely high - I hope to not ever reach it in my lifetime! Whatever your environment, a little trial-and-error can be used. Simply run something like 'java -Xmx2048M foo'. This is trying to set it to 2GB. Change the numeric value up and down to find out what your limit is. The Sun JRE gives an error about allocating the memory before worrying about not finding foo. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Monday, November 26, 2007 12:12 PM To: Tomcat Users List Subject: Re: is there a limit to JAVA Heap size ? Microsoft allows 3GB capability for User Process Address Space http://www.microsoft.com/technet/sysinternals/information/bootini.mspx Anyone else? M-- ----- Original Message ----- Wrom: UZXUWLSZLKBRNVWWCUFPEGAUTFJMVRESKPNKMBIPB To: "Tomcat Users List" <users@tomcat.apache.org> Sent: Monday, November 26, 2007 12:08 PM Subject: Re: is there a limit to JAVA Heap size ? > Jean, > > I am not a Tomcat Expert, though I know you can set this value to a > higher number. I have set once to 1GB. > > Perhaps the gurus on the forum would answer it clearly to you. > > HTH< > > Bruno > > On Nov 26, 2007 3:06 PM, Jean-Pierre Astier <[EMAIL PROTECTED]> wrote: > > Hello, > > > > An other little question !!! > > > > Is there a limit to the java heap size var environment ? > > > > There is 3 GB off RAM on my server. > > > > I've set JAVA_OPTS to -Xms512m -Xmx512m in catalina.sh. > > > > Can I increase more than this value ? > > > > Thanks > > > > --------------------------------------------------------------------- > > To start a new topic, e-mail: users@tomcat.apache.org > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]