Re: OT: java memory question -Xmx2048m
En l'instant précis du 25/02/08 13:51, Dave s'exprimait en ces termes: Our Linux(FC) machine has 8G physical memory and 12G swap size. I am using JDK 1.5. I tried to set the Java option -Xmx to set max heap size for best performance, the allowed max heap size is 2048M . Does that mean that the JVM can not use all the physical memory (8G) ? Thanks. Dave - Never miss a thing. Make Yahoo your homepage. The maximum memory the JVM can use depends on the maximum size of continuous memory segment the OS you run on allows you to reserve. On 32 bits linux, it's about 2G (that is 4G minus memory area reserved for kernel, minus memory area used by libraries minus other thingies jvm might use). To get more you will need a 64bits JVM + a 64 bits OS. Note it's a limitation of hardware architecture and OS more than a limitation of JVM. PS: if you plan to swap-out 12G of datas, i hope your disks are fast :) -- http://www.devlog.be (a belgian developer's logs) - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: OT: java memory question -Xmx2048m
Hi everyOne From adobe Faq On 32-bit processor machines, the largest contiguous memory address space the operating system can allocate to a process is 1.8GB. Because of this, the maximum heap size can only be set up to 1.8GB. On 64-bit processor machines, the 1.8 GB limit does not apply, as 64-bit processor machines have a larger memory address space. regards Roland Dave a écrit : Our Linux(FC) machine has 8G physical memory and 12G swap size. I am using JDK 1.5. I tried to set the Java option -Xmx to set max heap size for best performance, the allowed max heap size is 2048M . Does that mean that the JVM can not use all the physical memory (8G) ? Thanks. Dave - Never miss a thing. Make Yahoo your homepage. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: OT: java memory question -Xmx2048m
Dave wrote: Our Linux(FC) machine has 8G physical memory and 12G swap size. Happy swapping ;-) -- Mikolaj Rydzewski [EMAIL PROTECTED] smime.p7s Description: S/MIME Cryptographic Signature
Re: OT: java memory question -Xmx2048m
I installed Linux FC6 64-bit on the machine DELL 2590(I think it is INTEL type CPU). But JVM 64-bit is only available for AMD and SPARC. Is the SUN not support INTEL? Thanks, Dave David Delbecq [EMAIL PROTECTED] wrote: En l'instant précis du 25/02/08 13:51, Dave s'exprimait en ces termes: Our Linux(FC) machine has 8G physical memory and 12G swap size. I am using JDK 1.5. I tried to set the Java option -Xmx to set max heap size for best performance, the allowed max heap size is 2048M . Does that mean that the JVM can not use all the physical memory (8G) ? Thanks. Dave - Never miss a thing. Make Yahoo your homepage. The maximum memory the JVM can use depends on the maximum size of continuous memory segment the OS you run on allows you to reserve. On 32 bits linux, it's about 2G (that is 4G minus memory area reserved for kernel, minus memory area used by libraries minus other thingies jvm might use). To get more you will need a 64bits JVM + a 64 bits OS. Note it's a limitation of hardware architecture and OS more than a limitation of JVM. PS: if you plan to swap-out 12G of datas, i hope your disks are fast :) -- http://www.devlog.be (a belgian developer's logs) - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - Never miss a thing. Make Yahoo your homepage.
Re: OT: java memory question -Xmx2048m
For some reason Linux always calls 64 bit OSes 'AMD' - in fact, the sun 64 bit AMD version works fine on modern 64 bit Intel CPUs. The confusion comes because there was an older 64 bit design from Intel called the 'Itanium' which was intended for servers and had a completely different instruction set. The Xeon family and the E64 family are all compatible with the 'AMD' 64 bit JVM You say DELL 2590 - do you mean DELL 2950? The 2950 is takes Intel Xeon processors which will work with the so-called 'AMD' JVM. Hope that helps Regards Alan Chaney Dave wrote: I installed Linux FC6 64-bit on the machine DELL 2590(I think it is INTEL type CPU). But JVM 64-bit is only available for AMD and SPARC. Is the SUN not support INTEL? Thanks, Dave David Delbecq [EMAIL PROTECTED] wrote: En l'instant précis du 25/02/08 13:51, Dave s'exprimait en ces termes: Our Linux(FC) machine has 8G physical memory and 12G swap size. I am using JDK 1.5. I tried to set the Java option -Xmx to set max heap size for best performance, the allowed max heap size is 2048M . Does that mean that the JVM can not use all the physical memory (8G) ? Thanks. Dave - Never miss a thing. Make Yahoo your homepage. The maximum memory the JVM can use depends on the maximum size of continuous memory segment the OS you run on allows you to reserve. On 32 bits linux, it's about 2G (that is 4G minus memory area reserved for kernel, minus memory area used by libraries minus other thingies jvm might use). To get more you will need a 64bits JVM + a 64 bits OS. Note it's a limitation of hardware architecture and OS more than a limitation of JVM. PS: if you plan to swap-out 12G of datas, i hope your disks are fast :) - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
